High efficiency, high output transmission

ABSTRACT

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to the following U.S. ProvisionalPatent Application Ser. No. 62/438,201, filed Dec. 22, 2016, entitled“HIGH EFFICIENCY, HIGH OUTPUT TRANSMISSION”; and Ser. No. 62/465,021,filed Feb. 28, 2017, entitled “SYSTEM, METHOD, AND APPARATUS FORCONTROLLING A HIGH OUTPUT, HIGH EFFICIENCY TRANSMISSION”, each of whichis incorporated herein by reference in their entirety.

BACKGROUND Field

Without limitation to a particular field of technology, the presentdisclosure is directed to transmissions configured for coupling to aprime mover, and more particularly to transmissions for vehicleapplications, including truck applications.

Transmissions serve a critical function in translating power provided bya prime mover to a final load. The transmission serves to provide speedratio changing between the prime mover output (e.g. a rotating shaft)and a load driving input (e.g. a rotating shaft coupled to wheels, apump, or other device responsive to the driving shaft). The ability toprovide selectable speed ratios allows the transmission to amplifytorque, keep the prime mover and load speeds within ranges desired forthose devices, and to selectively disconnect the prime mover from theload at certain operating conditions.

Transmissions are subjected to a number of conflicting constraints andoperating requirements. For example, the transmission must be able toprovide the desired range of torque multiplication while still handlingthe input torque requirements of the system. Additionally, from the viewof the overall system, the transmission represents an overheaddevice—the space occupied by the transmission, the weight, and interfacerequirements of the transmission are all overhead aspects to thedesigner of the system. Transmission systems are highly complex, andthey take a long time to design, integrate, and test; accordingly, thetransmission is also often required to meet the expectations of thesystem integrator relative to previous or historical transmissions. Forexample, a reduction of the space occupied by a transmission may bedesirable in the long run, but for a given system design it may be moredesirable that an occupied space be identical to a previous generationtransmission, or as close as possible.

Previously known transmission systems suffer from one or more drawbackswithin a system as described following. To manage noise, robustness, andstructural integrity concerns, previously known high output transmissionsystems use steel for the housing of the transmission. Additionally,previously known high output transmissions utilize a large countershaftwith high strength spur gears to manage the high loads through thetransmission. Previously known gear sets have relatively few designdegrees of freedom, meaning that any shortcomings in the design need tobe taken up in the surrounding transmission elements. For example,thrust loads through the transmission, noise generated by gears, andinstallation issues such as complex gear timing issues, require a robustand potentially overdesigned system in the housing, bearings, and/orinstallation procedures. Previously known high output transmissions,such as for trucks, typically include multiple interfaces to thesurrounding system (e.g. electrical, air, hydraulic, and/or coolant),each one requiring expense of design and integration, and eachintroducing a failure point into the system. Previously known highoutput transmissions include a cooler to protect the parts and fluids ofthe transmission from overheating in response to the heat generated inthe transmission. Previously known high output transmissions utilizeconcentric clutches which require complex actuation and service.Accordingly, there remains a need for improvements in the design of highoutput transmissions, particularly truck transmissions.

SUMMARY

An example transmission includes an input shaft configured to couple toa prime mover, a countershaft having a first number of gears mountedthereon, a main shaft having a second number of gears mounted thereon, ashifting actuator that selectively couples the input shaft to the mainshaft by rotatably coupling at least one of the first number of gears tothe countershaft and/or coupling the second number of gears to the mainshaft, where the shifting actuator is mounted on an exterior wall of ahousing, and where the countershaft and the main shaft are at leastpartially positioned within the housing.

Certain further embodiments of an example transmission are describedfollowing. An example transmission includes an integrated actuatorhousing, where the shifting actuator is operationally coupled to theintegrated actuator housing, and where the shifting actuator isaccessible by removing the integrated actuator housing; a number ofshifting actuators operationally coupled to the integrated housingactuator, where the number of shifting actuators are accessible byremoving the integrated actuator housing; where the shifting actuator ismechanically coupled to the integrated actuator housing; and/or where anumber of shifting actuators are mechanically coupled to the integratedhousing actuator. An example transmission includes a clutch actuatoraccessible by removing the integrated actuator housing; where the clutchactuator is a linear clutch actuator; the example transmission furtherincluding a clutch actuator housing; where the linear clutch actuator ispositioned at least partially within the clutch actuator housing; andwhere the clutch actuator housing coupled to the integrated actuatorhousing and/or included as a portion of the integrated actuator housing;where the integrated housing actuator includes a single external poweraccess, and/or where the single external power access includes an airsupply port. An example transmission includes the integrated actuatorhousing defining power connections between actuators operationallycoupled to the integrated actuator housing; where the integratedactuator housing is mounted on a vertically upper side of thetransmission; where the shifting actuators are accessible withoutdecoupling the input shaft from the prime mover; where the integratedactuator housing is accessible without decoupling the input shaft fromthe prime mover; where the linear clutch actuator is pneumaticallyactivated; where the linear clutch actuator has a first extendedposition and a second retracted position, and where the linear clutchactuator includes a near zero dead air volume in the second retractedposition; where the dead air volume includes an air volume on a supplyside of the linear clutch actuator that is present when the linearclutch actuator is retracted; and/or where the linear clutch actuatorhas a first extended position and a second retracted position, and wherethe second retracted position is stable over a selected service life ofa clutch operationally coupled to the linear clutch actuator.

An example transmission includes a driveline having an input shaft, amain shaft, and a countershaft that selectively couples the input shaftto the main shaft, a housing element with at least part of the drivelinepositioned in the housing, where the housing element includes aluminum,and where the transmission is a high output transmission. Certainfurther embodiments of an example transmission are described following.An example transmission includes the transmission having no cooler;where the countershaft selectively couples the input shaft to the mainshaft using helical gear meshes, and/or where the helical gear meshesprovide thrust management; where the housing does not takes thrust loadsfrom the driveline; where the helical gear meshes further provide thrustmanagement such that a bearing at a low speed differential position inthe transmission takes thrust loads from the driveline; and/or where thebearing taking thrust at a low speed differential position is a bearingoperationally coupled to the input shaft and the main shaft. An exampletransmission further includes a planetary gear assembly coupled to asecond main shaft, where the planetary gear assembly includes helicalgears; where the planetary gear assembly provides a thrust load inresponse to power transfer through the planetary gear assembly; wherethe first main shaft is rotationally coupled to the second main shaft;where the transmission does not include taper bearings in the driveline;where the countershaft is a high speed countershaft; where thetransmission includes a number of high speed countershafts; and where afirst gear ratio between the input shaft and the countershaft, a secondgear ratio between the countershaft and the main shaft, have a ratiowhere the second gear ratio is greater than the first gear ratio by atleast 1.25:1, at least 1.5:1, at least 1.75:1, at least 2:1, at least2.25:1, at least 2.5:1, at least 2.75:1, at least 3:1, at least 3.25:1,at least 3.5:1, at least 3.75:1, at least 4:1, at least 4.25:1, at least4.5:1, at least 4.75:1, at least 5:1, at least 6:1, at least 7:1, atleast 8:1, at least 9:1, and/or at least 10:1.

An example transmission includes a driveline having an input shaft, amain shaft, and a countershaft that selectively couples the input shaftto the main shaft, and a low loss lubrication system. Certain furtherembodiments of an example transmission are described following. Anexample transmission includes the low loss lubrication system having adry sump; the low loss lubrication system having a lubrication pumpassembly positioned within the transmission; the low loss lubricationsystem including a lubrication pump rotationally coupled to thecountershaft, and/or where the countershaft is a high speedcountershaft; a lubrication sleeve positioned at least partially withinthe main shaft, and/or where the lubrication sleeve is an unsealedlubrication sleeve.

An example transmission includes a driveline having an input shaft, amain shaft, and a countershaft that selectively couples the input shaftto the main shaft, a countershaft that includes a number of gearsmounted thereon, and a power take-off (PTO) access positioned inproximity to at least one of the number of gears. Certain furtherembodiments of an example transmission are described following. Anexample transmission includes the PTO access being an 8-bolt PTO access;the transmission including an aluminum housing; the transmission furtherhaving a first end engaging a prime mover and a second end having anoutput shaft, and a second PTO access positioned at the second end;where the transmission is an automated manual transmission; and/or asecond countershaft, where the PTO access is positioned in proximity tothe countershaft or the second countershaft.

An example transmission includes an input shaft configured to couple toa prime mover, a countershaft having a first number of gears mountedthereon, a main shaft having a second number of gears mounted thereon,where the first number of gears and the second number of gears arehelical gears, and where the transmission is a high output transmission.Certain further embodiment of an example transmission are describedfollowing. An example transmission includes an aluminum housing, wherethe main shaft and the countershaft are at least partially positioned inthe housing; a bearing pressed into the housing, where the helical gearsmanage thrust loads such that the bearing pressed into the housing doesnot experience thrust loads; where the first number of gears and secondnumber of gears include a shortened tooth height and/or a flattened topgeometry.

An example clutch assembly includes a clutch disc configured to engage aprime mover, a pressure plate having a clutch biasing element, where theclutch engagement member couples to a clutch actuation element at anengagement position, and where a clutch adjustment member maintains aconsistent engagement position as a face of the clutch disc experienceswear. Certain further embodiments of an example clutch assembly aredescribed following. An example clutch assembly includes the clutchadjustment member having a cam ring operable to rotate in response toclutch disc wear; a pressure plate defining the clutch biasing elementand the clutch adjustment member; the pressure plate further definingaccess holes for the clutch adjustment member; the clutch assemblyfurther including an anti-rotation member operationally coupled to theclutch adjustment member to enforce one-way movement of the clutchadjustment member; and/or the pressure plate further defining at leastone access channel for the anti-rotation member.

Architectures for high output, high efficiency, low noise and otherwiseimproved automated transmissions are disclosed herein, includingmethods, systems, and components for automated truck transmissions. Suchmethods and systems may include, among other things, a pair of highspeed, twin countershafts. Architectures for 18-speed (including 3×3×2architectures with three gear boxes) and 12-speed (including 3×2×2architectures with three gear boxes) are disclosed. In embodiments, suchmethods and systems include methods and systems for thrust loadcancellation, including cancellation of loads across a helical or sungear used in at least one gear box of the transmission. In embodiments,enclosures, such as for the clutch and various gears are configured suchthat enclosure bearings are isolated from thrust loads, among otherthings allowing for use of lightweight materials, such as die castaluminum, for various components of the transmission, withoutcompromising performance or durability. A low-loss lubrication systemmay be provided for various components of the transmission.

In embodiments, clutch actuation (including for a linear clutch actuatorthat may actuate movement of a use a horseshoe, or off-axis, clutchactuator) and gear shift actuation for an automated truck transmissionare handled through an integrated electrical and mechanical assembly,which may be mounted in a mounted transmission module (MTM) on thetransmission, and which may use a common, integrated air supply forpneumatic actuation of clutch and gear systems, optionally employingintegrated conduits, rather than hoses, to reduce the free volume of airand thereby enhance the efficiency, reliability and performance of thegear and clutch actuation systems. The MTM may include a linear clutchactuator, position sensor and valve banks for gear and clutch actuation.

Gear systems, including substantially circular gears and helical gears,may be optimized to reduce noise and provide smooth shifting. Circulargears may have substantially flat teeth, may be wormwheel-ground toprovide smooth surfaces, and may be provided with profiles optimized toprovide optimized sliding velocity of engagement during gear shifts. Thetransmission may power power-take off (PTO) interfaces, optionallyincluding multiple PTO interfaces.

An example method includes an operation to provide a first opposingpulse, the first opposing pulse including a first predetermined amountof air above an ambient amount of air in a first closed volume, wherepressure in the first closed volume opposes movement of a shift actuatorin a shift direction, an operation to provide a first actuating pulse,the first actuating pulse including a second predetermined amount of airabove an ambient amount of air in a second closed volume, where pressurein the second closed volume promotes movement of the shift actuator inthe shift direction, and an operation to release pressure in the firstclosed volume and the second closed volume in response to determining ashift completion event.

Certain further operations of the example method are describedfollowing, any one or more of which may be included in certainembodiments. The example method further includes: an operation toprovide the first actuating pulse as two split pulses, where a first oneof the two split pulses is smaller than a first one of the two pulses;where a second one of the two split pulses includes an amount of airsubstantially equal to the first predetermined amount of air; and/orwhere the first one of the two split pulses includes an amount such as:between one-tenth and one-fourth of a total amount of air provided bythe two split pulses, less than 40% of a total amount of air provided bythe two split pulses, less than 33% of a total amount of air provided bythe two split pulses, less than 25% of a total amount of air provided bythe two split pulses and/or less than 20% of a total amount of airprovided by the two split pulses. The example method further includes:the first opposing pulse is performed at least 100 milliseconds (msec)before the first actuating pulse; the first actuating pulse is performedwithin a 200 msec window; an operation to determine that a synchronizerengagement is imminent, and to provide the first opposing pulse inresponse to the imminent synchronizer engagement; providing the secondpredetermined amount of air by determining the second predeterminedamount of air in response to a velocity of a shift actuator and a targetvelocity of a shift actuator; an operation to determine that asynchronizer is in an unblocked condition, and to provide a secondopposing pulse in response to the synchronizer being in the unblockedcondition; where determining that a synchronizer is in an unblockedcondition includes an operation such as: determining that a speeddifferential between engaging shafts is lower than an unblockingthreshold value, determining that a speed differential between engagingshafts is within a predetermined unblocking range value, determiningthat a synchronizer engagement time value has elapsed, and/ordetermining that a shift actuator position value indicates theunblocking condition. The example method further includes: an operationto determine that a synchronizer is in an unblocked condition, and toprovide a second opposing pulse in response to the synchronizer being inthe unblocked condition; where determining that the synchronizer is inan unblocked condition includes at least one operation such as:determining that a speed differential between engaging shafts is lowerthan an unblocking threshold value, determining that a speeddifferential between engaging shafts is within a predeterminedunblocking range value, determining that a synchronizer engagement timevalue has elapsed, and/or determining that a shift actuator positionvalue indicates the unblocking condition. The example method furtherincludes: where the first actuating pulse includes apulse-width-modulated operation; an operation to determine a shiftactuator position value, and to modify a duration of the first actuatingpulse in response to the shift actuator position value; an operation todetermine a shift actuator position value, and to modulate the firstactuating pulse in response to the shift actuator position value; wherethe shift actuator position value includes at least one of: aquantitative position description of the shift actuator; a quantitativevelocity description of the shift actuator; and/or a shift statedescription value corresponding to the shift actuator; where the shiftstate description value includes at least one of: a neutral position; aneutral departure position; a synchronizer engagement approach position;a synching position; a synchronizer unblock position; an engagedposition; and/or a disengaging position.

Certain further operations of the example method are describedfollowing, any one or more of which may be included in certainembodiments. The example method further includes where the firstactuating pulse includes a shaped air provision trajectory; where the pfirst actuating pulse includes at least one operation to open and closea binary pneumatic valve; an operation to determine at least one shaftspeed value, and to determine the predetermined first air amount inresponse to the at least one shaft speed value; an operation todetermine an air supply pressure value, and to determine thepredetermined first air amount in response to the air supply pressurevalue; an operation to determine at least one temperature value, and todetermine the predetermined first air amount in response to the at leastone temperature value; an operation to determine the predetermined firstair amount in response to at least one of: at least one shaft speedvalue, an air supply pressure value, and/or at least one temperaturevalue; an operation to determine at least one shaft speed value, and todetermine a timing of the predetermined first air amount in response tothe at least one shaft speed value; an operation to determine an airsupply pressure value, and to determine a timing of the predeterminedfirst air amount in response to the air supply pressure value; anoperation to determine at least one temperature value, and to determinea timing of the predetermined first air amount in response to the atleast one temperature value; an operation to determine a timing of thepredetermined first air amount in response to at least one value suchas: at least one shaft speed value, an air supply pressure value, and/orat least one temperature value; an operation to determine a reflecteddriveline inertia value, and to determine the predetermined first airamount in response to the reflected driveline inertia value; anoperation to determine a reflected driveline inertia value, and todetermine a timing of the predetermined first air amount in response tothe reflected driveline inertia value; determining the predeterminedfirst air amount in response to at least one value such as: at least oneshaft speed value, an air supply pressure value, at least onetemperature value, and/or a reflected driveline inertia value.

Certain further operations of the example method are describedfollowing, any one or more of which may be included in certainembodiments. An operation to determine a timing of the predeterminedfirst air amount in response to at least one value such as: at least oneshaft speed value, an air supply pressure value, at least onetemperature value, and/or a reflected driveline inertia value; anoperation to determine a shift actuator position value, and to adjust atleast one of the first actuating pulse and the first opposing pulse inresponse to the shift actuator position value; where adjusting includesinterrupting the first actuating pulse and/or the first opposing pulseto synchronize pressure decay in the first closed volume and the secondclosed volume; an operation to determine a shift actuator positionvalue, and adjusting the first actuating pulse and/or the secondopposing pulse in response to the shift actuator position value, and/orwhere adjusting includes interrupting the first actuating pulse and thesecond opposing pulse to synchronize pressure decay in the first closedvolume and the second closed volume; where modulating the firstactuation pulse includes reducing the second predetermined amount of airin response to the shift actuator position value being a shift statedescription value, and/or reducing the first actuating pulse in responseto the shift state description value; where reducing the first actuatingpulse includes limiting an air pressure build-up in the second closedvolume; where first shift actuator position value includes a shift statedescription, and where modulating includes reducing the secondpredetermined amount of air in response to the shift state descriptionindicating a synching position; where reducing the first actuating pulseincludes limiting an air pressure build-up in the second closed volume;where providing the first actuating pulse is commenced before theproviding the first opposing pulse is commenced.

Certain further operations of the example method are describedfollowing, any one or more of which may be included in certainembodiments. The example method further includes an operation to providea third opposing pulse, the third opposing pulse including a thirdpredetermined amount of air above an ambient amount of air in a thirdclosed volume, where pressure in the third closed volume opposesmovement of a second shift actuator in a shift direction, an operationto provide a second actuating pulse, the second actuating pulseincluding a fourth predetermined amount of air above an ambient amountof air in a fourth closed volume, where pressure in the fourth closedvolume promotes movement of the second shift actuator in the shiftdirection, and an operation to release pressure in the third closedvolume and the fourth closed volume in response to determining a secondshift completion event; and/or where the first opposing pulse, the thirdopposing pulse, the first actuating pulse, and the second actuatingpulse are performed such that not more than one actuating valve is opensimultaneously.

Another example method includes an operation to engage a friction braketo a countershaft of a transmission, to track an engaged time of thefriction brake, to determine a target release time for the frictionbrake, to determine a release delay for the friction brake in responseto the engaged time, and to command a release of the friction brake inresponse to the release delay and the target release time.

Certain further aspects of the example method are described following,any one or more of which may be included in certain embodiments. Theexample method further includes determining the release delay bydetermining a pressure decay value in a friction brake actuation volume;where determining the pressure decay value includes an operation todetermine a pressure in the friction brake actuation volume; wheredetermining the pressure decay value includes utilizing a pre-determinedrelationship between engaged time and pressure decay in the frictionbrake actuation volume; an operation to determine a speed differentialbetween the countershaft and an engaging shaft, and to determine thetarget release time further in response to the speed differential; wherethe engaging shaft includes at least one shaft such as: an output shaft,a main shaft, and/or an input shaft; an operation to determine a lumpeddriveline stiffness value, and to determine the target release timefurther in response to the lumped driveline stiffness value; anoperation to determine a target gear ratio value, and to determine thetarget release time further in response to the target gear ratio value;an operation to determine a friction brake disengagement dynamic value,and to determine the target release time further in response to thefriction brake disengagement dynamic value; an operation to determine avehicle speed effect, and to determine the target release time furtherin response to the vehicle speed effect; where the vehicle speed effectincludes at least one effect such as: a current vehicle speed, anestimated vehicle speed at a gear engagement time, a vehicleacceleration rate, and/or a vehicle deceleration rate. An exampleapparatus includes a backlash indication circuit that identifies animminent backlash crossing event at a first gear mesh, and a means forreducing engagement force experienced by the first gear mesh in responseto the backlash crossing event. Certain non-limiting examples of themeans for reducing engagement force experienced by the first gear meshin response to the backlash crossing event are described following. Anexample means for reducing engagement force experienced by the firstgear mesh further includes means for performing at least one operationsuch as: disengaging the first gear mesh during at least a portion ofthe backlash crossing event, disengaging a clutch during at least aportion of the backlash crossing event, and slipping a clutch during atleast a portion of the backlash crossing event. An example apparatusincludes the backlash indication circuit further identifying theimminent backlash crossing event by determining that a gear shiftoccurring at a second gear mesh is likely to induce the backlashcrossing event at the first gear mesh, and where the means for reducingengagement force experienced by the first gear mesh further includes ameans for disengaging the first gear mesh during at least of portion ofthe gear shift. An example apparatus includes the means for reducingengagement force experienced by the first gear mesh further including afirst gear mesh pre-load circuit that provides a disengagement pulsecommand, where the apparatus further includes a shift actuatorresponsive to the disengagement pulse command; where the first gear meshpre-load circuit further provides the disengagement pulse command beforethe backlash crossing event occurs; where the disengagement pulsecommand includes a fifth predetermined amount of air above an ambientamount of air in a fifth closed volume, and where pressure in the fifthclosed volume promotes movement of the shift actuator in thedisengagement direction; where the disengagement pulse command furtherincludes a sixth predetermined amount of air above an ambient amount ofair in a sixth closed volume, where pressure in the sixth closed volumeopposes movement of the shift actuator in the disengagement direction;where the first gear pre-load circuit further determines the fifthpredetermined amount of air and the sixth predetermined amount of airsuch that the shift actuator is urged into a neutral position inresponse to a release of engagement force; where the first gear pre-loadcircuit further provides the disengagement pulse command before a firstbacklash crossing of the backlash crossing event; and/or where the firstgear pre-load circuit further provides the disengagement pulse commandbefore a subsequent backlash crossing of the backlash crossing event. Anexample apparatus includes the backlash indication circuit furtheridentifies the imminent backlash crossing event by performing at leastone operation such as: determining that an imminent rotational directionof the first gear mesh in a transmission is an opposite rotationaldirection to an established rotational direction of the first gear mesh,determining that a speed change between a first shaft comprising gearson one side of the first gear mesh and a second shaft comprising gearson an opposing side of the first gear mesh is likely to induce thebacklash crossing event, determining that a gear shift occurring at asecond gear mesh is likely to induce the backlash crossing event at thefirst gear mesh, determining that a transmission input torque value isat an imminent zero crossing event, and/or determining that a vehicleoperating condition is likely to induce the backlash crossing event.

An example system includes and/or interacts with a prime mover providingmotive torque, and the system includes a torque transfer pathoperatively coupling the motive torque to drive wheels, the torquetransfer path including: a clutch that selectively decouples the primemover from an input shaft of the torque transfer path, where the inputshaft is operationally downstream of the clutch; a first gear mesh and asecond gear mesh, each gear mesh having an engaged and a neutralposition, and where both gear meshes in the engaged position couple theinput shaft to the drive wheels, and where either gear mesh in theneutral position decouples the input shaft from the drive wheels; afirst shift actuator that selectively operates the first gear meshbetween the engaged and neutral position; a second shift actuator thatselectively operates the second gear mesh between the engaged andneutral position; and a controller including: a vehicle state circuitthat interprets at least one vehicle operating condition; a neutralenforcement circuit that provides a first neutral command to the firstshift actuator and a second neutral command to the second shiftactuator, in response to the vehicle operating condition indicating thatvehicle motion is not intended.

Certain example aspects of the example system are described following,any one or more of which may be included in certain embodiments. Anexample system further includes the at least one vehicle operationcondition including at least one value such as: an engine crank statevalue, a gear selection value, a vehicle idling state value, and/or aclutch calibration state value; the vehicle state circuit furtherdetermining a vehicle stopped condition, and where the neutralenforcement circuit further provides the first neutral command and thesecond neutral command in response to the vehicle stopped condition; thecontroller further including a shift rail actuator diagnostic circuitthat diagnoses proper operation of at least one shift rail positionsensor in response to a vehicle speed value; the vehicle state circuitfurther interpreting at least one failure condition, and providing avehicle stopping distance mitigation value in response to the at leastone failure condition; the controller further including a clutchoverride circuit that provides a forced clutch engagement command inresponse to the vehicle stopping distance mitigation value; where theclutch override circuit further provides a forced clutch engagementcommand in response to the vehicle stopping distance mitigation value,and further in response to at least one value such as: a motive torquevalue representative of the motive torque, an engine speed valuerepresentative of a speed of the prime mover, an accelerator positionvalue representative of an accelerator pedal position, a service brakeposition value representative of a position of a service brake position,a vehicle speed value representative of a speed of the drive wheels,and/or a service brake diagnostic value.

Another example system includes a clutch that selectively decouples aprime mover from an input shaft of a transmission, a progressiveactuator operationally coupled to the clutch, where a position of theprogressive actuator corresponds to a position of the clutch, and acontroller including: a clutch characterization circuit that interpretsa clutch torque profile, the clutch torque profile providing a relationbetween a position of the clutch and a clutch torque value, a clutchcontrol circuit that commands a position of the progressive actuator inresponse to a clutch torque reference value and the clutch torqueprofile, and where the clutch characterization circuit furtherinterprets a position of the progressive actuator and an indicatedclutch torque, and updates the clutch torque profile in response to theposition of the progressive actuator and the indicated clutch torque.

Certain further aspects of the example system are described following,any one or more of which may be included in certain embodiments. Anexample system includes the clutch torque profile including a firstclutch engagement position value, and where the clutch control circuitfurther utilizes the first clutch engagement position value as a maximumzero torque position; where the clutch characterization circuit furtherinterprets the clutch torque profile by performing a clutch firstengagement position test, the clutch first engagement position testincluding: determining that an input shaft speed is zero, the clutchcontrol circuit positioning the clutch at the first engagement positionvalue, and comparing an acceleration of the input shaft speed to a firstexpected acceleration value of the input shaft speed; the clutchcharacterization circuit further performing the clutch first engagementposition test a number of times; the clutch first engagement positiontest further including a friction brake control circuit that commands afriction brake to bring the input shaft speed to zero; where the clutchtorque profile includes a second clutch engagement position value, andwherein the clutch control circuit further utilizes the second clutchengagement position value as a minimum significant engagement torqueposition; where the clutch characterization circuit further interpretsthe clutch torque profile by performing a clutch second engagementposition test, the clutch second engagement position test including:determining that an input shaft speed is zero, the clutch controlcircuit positioning the clutch at the second engagement position value,and comparing an acceleration of the input shaft speed to a secondexpected acceleration value of the input shaft speed; where the clutchcharacterization circuit further performs the clutch second engagementposition test a number of times; where the clutch second engagementposition test further includes a friction brake control circuit thatcommands a friction brake to bring the input shaft speed to zero; wherethe clutch torque profile includes a first clutch engagement positionvalue and a second clutch engagement position value, and/or where theclutch control circuit further utilizes the first clutch engagementposition value as a maximum zero torque position and utilizes the secondclutch engagement position value as a minimum significant engagementtorque position. An example system further includes the clutch torqueprofile further including a clutch torque curve including a number ofclutch position values corresponding to a number of clutch torquevalues, where each of the clutch position values is greater than thesecond clutch engagement position value; where the clutchcharacterization circuit further interprets the clutch torque profile byperforming a clutch second engagement position test, the clutch secondengagement position test including determining that an input shaft speedis zero, the clutch control circuit positioning the clutch at the secondengagement position value, and comparing an acceleration of the inputshaft speed to a second expected acceleration value of the input shaftspeed, and adjusting the clutch torque curve in response to a change inthe clutch second engagement position; where the clutch characterizationcircuit further determines that the clutch is operating in awear-through mode in response to at least one of the first engagementposition value and the second engagement position value changing at arate greater than a clutch wear-through rate value; and/or where thecontroller further includes a clutch wear circuit that determines aclutch wear value in response to a clutch temperature value, a clutchpower throughput value, and/or a clutch slip condition, and where theclutch characterization circuit further updates the clutch torqueprofile in response to the clutch wear value.

An example method includes an operation to interpret a clutchtemperature value, to interpret a clutch power throughput value, tointerpret that a clutch is in a slip condition, and, in response to theclutch temperature value, the clutch power throughput value, and theclutch slip condition, to determine a clutch wear value.

Certain further operations for the example method are describedfollowing, any one or more of which may be included in certainembodiments. An example method includes determining the clutch wearvalue includes accumulating a clutch wear index, the clutch wear indexdetermined in response to the clutch temperature value, the clutch powerthroughput value, and the clutch slip condition; determining that aclutch is in a wear-through mode in response to the clutch wear indexexceeding a wear-through threshold value; providing a clutch diagnosticvalue in response to the clutch wear index; and/or where providing theclutch diagnostic value includes at least one operation such as:providing a clutch wear fault value, incrementing a clutch wear faultvalue, communicating the clutch diagnostic value to a data link, and/orproviding the clutch diagnostic value to a non-transient memory locationaccessible to a service tool.

An example system includes a clutch that selectively decouples a primemover from an input shaft of a transmission, a progressive actuatoroperationally coupled to the clutch, where a position of the progressiveactuator corresponds to a position of the clutch, and a means forproviding a consistent lock-up time of the clutch, the lock-up timecomprising a time commencing with a clutch torque request time andending with a clutch lock-up event. Certain non-limiting examples of themeans for providing a consistent lock-up time of the clutch aredescribed following. An example means for providing the consistentlock-up time of the clutch includes a controller having a clutch controlcircuit, where the clutch control circuit commands a position of theprogressive actuator in response to a clutch torque reference value andthe clutch torque profile to achieve the consistent lock-up time of theclutch; where the progressive actuator includes a linear clutchactuator; and/or where the linear clutch actuator includes a near zerodead air volume. An example means for providing the consistent lock-uptime of the clutch further includes a controller having a launchcharacterization circuit, the launch characterization circuit structuredto interpret at least one launch parameter such as: a vehicle gradevalue, a vehicle mass value, and/or a driveline configuration value;and/or where the driveline configuration value includes at least onevalue such as: a target engagement gear description, a reflecteddriveline inertia value, and/or a vehicle speed value. An example meansfor providing the consistent lock-up time of the clutch further includesa controller having a clutch control circuit, where the clutch controlcircuit commands a position of the progressive actuator in response to aclutch torque reference value, the clutch torque profile, and at leastone launch parameter to achieve the consistent lock-up time of theclutch; and/or where the clutch control circuit further commands theposition of the progressive actuator in response to a clutch slipfeedback value. An example means for providing the consistent lock-uptime of the clutch further includes a controller having a clutch controlcircuit, where the clutch control circuit commands a position of theprogressive actuator in response to a clutch torque reference value, theclutch torque profile, and/or a clutch slip feedback value. An examplesystem further includes the clutch torque request time including atleast one request condition such as: a service brake pedal releaseevent, a service brake pedal decrease event, a gear engagement requestevent, and/or a prime mover torque increase event; and/or where theclutch lock-up event includes a clutch slip value being lower than aclutch lock-up slip threshold value.

An example method includes an operation to interpreting a motive torquevalue, a vehicle grade value, and a vehicle acceleration value; todetermine a first correlation including a first correlation between themotive torque value and the vehicle grade value, to determine a secondcorrelation between the motive torque value and the vehicle accelerationvalue, and to determine a third correlation between the vehicle gradevalue and the vehicle acceleration value, an operation to adapt anestimated vehicle mass value, an estimated vehicle drag value, and anestimated vehicle effective inertia value in response to the firstcorrelation, the second correlation, and the third correlation, anoperation to determine an adaptation consistency value, and in responseto the adaptation consistency value, to adjust an adaptation rate of theadapting, and an operation to iteratively perform the precedingoperations to provide an updated estimated vehicle mass value.

Certain further operations of the example method are describedfollowing, any one or more of which may be included in certainembodiments. An example method includes adapting by one of slowing orhalting adapting of the estimated values in response to the firstcorrelation, the second correlation, and the third correlation having anunexpected correlation configuration; adapting by increasing orcontinuing adapting the estimated values in response to the firstcorrelation, the second correlation, and the third correlation having anexpected correlation configuration; where the expected correlationconfiguration includes a positive correlation for the first correlationand the second correlation, and a negative correlation for the thirdcorrelation; where the expected correlation configuration furtherincludes a linearity value corresponding to each of the firstcorrelation, the second correlation, and the third correlation; wherethe adapting includes one of slowing or halting adapting the estimatedvalues in response to the first correlation, the second correlation, andthe third correlation having an unexpected correlation configuration;where the unexpected correlation includes a negative correlation for thefirst correlation and/or the second correlation, and/or a positivecorrelation for the third correlation. An example method includesadjusting the adaptation rate by increasing or holding an adjustmentstep size in the estimated vehicle mass value, the estimated vehicleeffective inertia value, and/or the estimated vehicle drag value inresponse to the adaptation performing at least one operation such as:monotonically changing each estimated value, and/or and monotonicallychanging at least one estimated value and holding the other estimatedvalue(s) at a same value; where adjusting the adaptation rate includesdecreasing an adjustment step size in estimated vehicle mass value, theestimated vehicle effective inertia value, and/or the estimated vehicledrag value in response to the adaptation changing a direction ofadaptation in at least one of the estimated values; and/or where theadjusting the adaptation rate is performed in response to the changingthe direction being a change greater than a threshold change.

An example method includes an operation to determine that a shift railposition sensor corresponding to a shift actuator controlling a reversegear is failed, to determine that a gear selection is active requiringoperations of the shift actuator, and in response to the gear selectionand the failed shift rail position sensor, performing in order:commanding the shift actuator to a neutral position, confirming theneutral position by commanding a second shift actuator to engage asecond gear, wherein the second shift actuator is not capable ofengaging the second gear unless the shift actuator is in the neutralposition, and confirming the second shift actuator has engaged thesecond gear, and commanding the shift actuator into the gear position inresponse to the gear selection.

Certain further operations of the example method are describedfollowing, any one or more of which may be included in certainembodiments. An example method includes determining the shift railposition sensor is failed by determining the shift rail position sensoris failed out of range; where determining the shift mil position sensoris failed includes determining the shift rail position sensor is failedin range; and/or where determining the shift rail position sensor isfailed in range includes, in order: commanding the shift actuator to theneutral position, commanding the shift actuator to an engaged position,determining if the shift actuator engaged position is detected, inresponse to the shift actuator engaged position not being detected,confirming the neutral position by: commanding the shift actuator to theneutral position, commanding a second shift actuator to engage a secondgear, where the second shift actuator is not capable of engaging thesecond gear unless the shift actuator is in the neutral positon, andconfirming the second shift actuator has engaged the second gear, anddetermining the shift rail position sensor is failed in range inresponse to the neutral position being confirmed, and determining ashift mil operated by the shift actuator is stuck in response to theneutral position not being confirmed.

An example system includes a transmission having a solenoid operatedactuator, and a controller including: a solenoid temperature circuitthat determines an operating temperature of the solenoid, a solenoidcontrol circuit that operates the solenoid in response to the operatingtemperature of the solenoid, where the operating includes providing anelectrical current to the solenoid, such that a target temperature ofthe solenoid is not exceeded.

Certain further aspects of the example system are described following,any one or more of which may be included in certain embodiments. Anexample system includes the solenoid temperature circuit furtherdetermining the operating temperature of the solenoid in response to anelectrical current value of the solenoid and an electrical resistancevalue of the solenoid; the solenoid temperature circuit furtherdetermining the operating temperature of the solenoid in response to athermal model of the solenoid; the solenoid operated actuator includinga reduced nominal capability solenoid; the solenoid operated actuatorincluding at least one actuator such as: a clutch actuator, a valveactuator, a shift rail actuator, and a friction brake actuator; and/orwhere the solenoid control circuit further operates the solenoid bymodulating at least one parameter such as: a voltage provided to thesolenoid, a cooldown time for the solenoid, and/or a duty cycle of thesolenoid.

An example system includes a transmission having at a pneumatic clutchactuator, a clutch position sensor configured to provide a clutchactuator position value, and a controller including: a clutch controlcircuit that provides a clutch actuator command, where the pneumaticclutch actuator is responsive to the clutch actuator command, and aclutch actuator diagnostic circuit that determines that a clutchactuator leak is present in response to the clutch actuator command andthe clutch actuator position value.

Certain further aspects of the example system are described following,any one or more of which may be included in certain embodiments. Anexample system includes the clutch actuator diagnostic circuit furtherdetermining the clutch actuator leak is present in response to theclutch actuator position value being below a threshold position valuefor a predetermined time period after the clutch actuator command isactive; where the clutch actuator diagnostic circuit further determinesthe clutch actuator leak is present in response to the clutch actuatorposition value being below a clutch actuator position trajectory value,the clutch actuator position trajectory value including a number ofclutch actuator position values corresponding to a plurality of timevalues; and the system further including a source pressure sensorconfigured to provide a source pressure value, and where the clutchactuator diagnostic circuit further determines the clutch actuator leakis present in response to the source pressure value.

An example system further includes a transmission having at least onegear mesh operatively coupled by a shift actuator, and a controllerincluding a shift characterization circuit that determines that atransmission shift operation is experiencing a tooth butt event, thesystem further including a means for clearing the tooth butt event.Certain non-limiting examples of the means for clearing the tooth buttevent are described following. An example means for clearing the toothbutt event includes the controller further including a shift controlcircuit, where the shift control circuit provides a reduced railpressure in a shift rail during at least a portion of the tooth buttevent, where the shift rail is in operationally coupled to the shiftactuator. An example means for clearing the tooth butt event includesthe controller including a clutch control circuit, where the clutchcontrol circuit modulates an input shaft speed in response to the toothbutt event, and/or where the clutch control circuit further modulatesthe input shaft speed by commanding a clutch slip event in response tothe tooth butt event. An example means for clearing the tooth butt eventincludes the controller including a friction brake control circuit,where the friction brake control circuit modulates a countershaft speedin response to the tooth butt event. An example means for clearing thetooth butt event includes a means for controlling a differential speedbetween shafts operationally coupled to the gear mesh to a selecteddifferential speed range, where the selected differential speed rangeincludes at least one speed range value such as: less than a 200 rpmdifference; less than a 100 rpm difference; less than a 50 rpmdifference; about a 50 rpm difference; between 10 rpm and 100 rpmdifference; between 10 rpm and 200 rpm difference; and/or between 10 rpmand 50 rpm difference.

An example system includes a clutch that selectively decouples a primemover from an input shaft of a transmission, a progressive actuatoroperationally coupled to the clutch, where a position of the progressiveactuator corresponds to a position of the clutch, and a means fordisengaging the clutch to provide a reduced driveline oscillation,improved driver comfort, and/or reduced part wear. Certain non-limitingexamples of the means for disengaging the clutch are describedfollowing. An example means for disengaging the clutch includes acontroller having a clutch control circuit that modulates a clutchcommand in response to at least one vehicle operating condition, andwhere the progressive actuator is responsive to the clutch command;where the at least one vehicle operating condition such as: a servicebrake position value, a service brake pressure value, a differentialspeed value between two shafts in a transmission including the clutchand progressive actuator, and/or an engine torque value; and/or wherethe clutch control circuit further modulates the clutch command toprovide a selected clutch slip amount.

These and other systems, methods, objects, features, and advantages ofthe present disclosure will be apparent to those skilled in the art fromthe following detailed description of the preferred embodiment and thedrawings.

All documents mentioned herein are hereby incorporated in their entiretyby reference. References to items in the singular should be understoodto include items in the plural, and vice versa, unless explicitly statedotherwise or clear from the text. Grammatical conjunctions are intendedto express any and all disjunctive and conjunctive combinations ofconjoined clauses, sentences, words, and the like, unless otherwisestated or clear from the context.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure and the following detailed description of certainembodiments thereof may be understood by reference to the followingfigures:

FIG. 1 depicts an example transmission.

FIG. 2 depicts an example transmission.

FIG. 3 depicts an example transmission.

FIG. 4 depicts an example transmission.

FIG. 5 depicts an example transmission.

FIG. 6 depicts an example transmission.

FIG. 7 depicts an example transmission.

FIG. 8 depicts a cutaway view of an example transmission.

FIG. 9 depicts a cutaway view of an example transmission.

FIG. 10 depicts a cutaway view of an example transmission.

FIG. 11 depicts an exploded view of an example transmission.

FIG. 12 depicts an exploded view of an example friction brake.

FIG. 13 depicts an example integrated actuation assembly.

FIG. 14 depicts an example transmission control module.

FIG. 15 depicts an example integrated actuation assembly.

FIG. 16 depicts an example lubrication pump assembly.

FIG. 17 depicts an exploded view of an example lubrication pumpassembly.

FIG. 18 depicts example bushing lubrication tubes in the context of anexample transmission.

FIG. 19 depicts an example bushing lubrication tube.

FIG. 20 depicts an example bushing lubrication tube.

FIG. 21 depicts an example bushing lubrication tube.

FIG. 22 depicts an example bushing lubrication tube.

FIG. 23 depicts a cutaway view of an example driveline assembly.

FIG. 24 depicts an example driveline assembly.

FIG. 25 depicts a cutaway view of an example driveline assembly.

FIG. 26 depicts a cutaway view of an example input shaft assembly.

FIG. 27 depicts a cutaway view of an example actuator assembly.

FIG. 28 depicts a cutaway view of an example input shaft end.

FIG. 29 depicts a cutaway view of an example main shaft portion.

FIG. 30 depicts a cutaway view of an example countershaft.

FIG. 31 depicts a detail of an example roller bearing.

FIG. 32 depicts a detail of an example roller bearing.

FIG. 33 depicts a cutaway view of an example countershaft.

FIG. 34 depicts a cutaway of an example planetary gear assembly.

FIG. 35 depicts a detail view of an example sliding clutch.

FIG. 36 depicts a detail view of an example output synchronizationassembly.

FIG. 37 depicts an example output shaft assembly portion.

FIG. 38 depicts an example planetary gear assembly portion.

FIG. 39 depicts an example shift actuator in proximity to a slidingclutch.

FIG. 40 depicts an example transmission.

FIG. 41 depicts an example exploded clutch assembly.

FIG. 42 depicts an example exploded clutch assembly.

FIG. 43 depicts an example pressure plate assembly.

FIG. 44 depicts an example pressure plate assembly.

FIG. 45 is a schematic flow diagram of a service event.

FIG. 46 is a schematic flow diagram of a service event.

FIG. 47 depicts an example clutch housing.

FIG. 48 depicts an example clutch housing.

FIG. 49 depicts an example rear housing.

FIG. 50 depicts an example rear housing.

FIG. 51 depicts an example rear housing.

FIG. 52 depicts an example lubrication pump assembly.

FIG. 53 depicts an example lubrication pump assembly.

FIG. 54 depicts an example main housing.

FIG. 55 depicts an example main housing.

FIG. 56 depicts an example main housing.

FIG. 57 depicts an example main housing.

FIG. 58 depicts an example main housing.

FIG. 59 is a schematic representation of a transmission having acontroller.

FIG. 60 is a schematic representation of a transmission having acontroller.

FIG. 61 is a schematic representation of a controller actuating aclutch.

FIG. 62 is a schematic flow diagram to control a shift actuator.

FIG. 63 is a schematic flow diagram to control a shift actuator.

FIG. 64 is a schematic flow diagram to control a shift actuator.

FIG. 65 is a schematic flow diagram to control a shift actuator.

FIG. 66 is a schematic flow diagram to control a shift actuator.

FIG. 67 is a schematic flow diagram to control a friction brake.

FIG. 68 is a schematic diagram of a controller to manage backlash.

FIG. 69 is a schematic representation of a transmission having acontroller.

FIG. 70 is a schematic diagram of a controller for a transmission.

FIG. 71 is a schematic representation of a controller actuating aclutch.

FIG. 72 is a schematic diagram of a controller for a transmission.

FIG. 73 is a schematic flow diagram to determine clutch control values.

FIG. 74 is a schematic flow diagram to determine clutch control values.

FIG. 75 is an illustration of example clutch torque profiles.

FIG. 76 is a schematic flow diagram to determine clutch wear.

FIG. 77 is a schematic flow diagram of a controller for a transmission.

FIG. 78 is a schematic flow diagram to determine a vehicle mass.

FIG. 79 is a schematic flow diagram to shift with a failed positionsensor.

FIG. 80 is a schematic flow diagram to diagnose a position sensor.

FIG. 81 is a schematic representation of a controller operating anactuator.

FIG. 82 is a schematic diagram of a controller operating an actuator.

FIG. 83 is a schematic representation of a controller detecting anactuator leak.

FIG. 84 is a schematic diagram of a controller for a transmission.

FIG. 85 is a schematic representation of a controller for atransmission.

FIG. 86 is a schematic diagram of a controller mitigating a tooth buttevent.

FIG. 87 is a schematic diagram of a controller operating a clutch.

FIG. 88 is a schematic diagram of a controller estimating systemparameters.

FIG. 89 is a schematic diagram of a controller operating a frictionbrake.

FIG. 90 is a schematic diagram of a controller operating a shiftactuator.

FIG. 91 is a schematic diagram of a controller operating a shiftactuator.

FIG. 92 is a schematic diagram of a controller operating a shiftactuator.

FIG. 93 is a schematic diagram of a controller mitigating a backlashevent.

DETAILED DESCRIPTION

Referencing FIG. 1, an example transmission 100 having one or moreaspects of the present disclosure is depicted. The example transmission100 includes a main housing 102, the main housing 102 defines the outershape of portions of the transmission 100 and in certain embodiments themain housing 102 includes one or more components made of aluminum. Theexample main housing 102 is coupled to a clutch housing 104, wherein theclutch housing 104 includes or is operationally coupled to a clutch 106.The example transmission 100 further includes a rear housing 108. Therear housing 108 provides aspects of the transmission 100 enclosure atthe rear, including in certain embodiments a planetary or helical gearset disposed within the rear housing 108, having structural engagementwith an output shaft assembly 110.

The example transmission 100 includes an integrated actuator housing 112coupled to the main housing 102. The integrated actuator housing 112 inthe example of FIG. 1 is coupled to the top of the transmission 100, andthe main housing 102 includes an opening (not shown) at the positionwhere the integrated actuator housing 112 coupled to the main housing102. In the example transmission 100 the opening in the main housing 102provides access for actuators operationally coupled to the integratedactuator housing 112, including for example a clutch actuator and/or oneor more gear shifting actuators. Example transmission 100 furtherincludes a transmission control module 114 (TCM), where the example TCM114 couples directly to the integrated actuator housing 112.

The arrangement of the aspects of the transmission 100 depicted in FIG.1 is an example and nonlimiting arrangement. Other arrangements ofvarious aspects are contemplated herein, although in certain embodimentsone or more of the arrangements depicted in FIG. 1 may be advantageousas described throughout the present disclosure. Particular arrangementsand aspects of the transmission 100 may be included in certainembodiments, including one or more of the aspects arranged as depicted,and one or more of the aspects arranged in a different manner as wouldbe understood to one of skill in the art contemplating a particularapplication and/or installation.

The description of spatial arrangements in the present disclosure, forexample front, rear, top, bottom, above, below, and the like areprovided for convenience of description and for clarity in describingthe relationship of components. The description of a particular spatialarrangement and/or relationship is nonlimiting to embodiments of atransmission 100 consistent with the present disclosure, in a particulartransmission 100 may be arranged in any manner understood in the art.For example, and without limitation, a particular transmission 100 maybe installed such that a “rear” position may be facing a front, side, orother direction as installed on a vehicle and/or application.Additionally or alternatively, the transmission 100 may be rotated andor tilted about any axis, for example and without limitation at anazimuthal angle relative to a driveline (e.g. the rotational angle ofthe clutch 106), and/or a tilting from front to back such as toaccommodate an angled driveline. Accordingly, one or more components maybe arranged relatively as described herein, and a component described asabove another component may nevertheless be the vertically lowercomponent as installed in a particular vehicle or application. Further,components for certain embodiments may be arranged in a relative mannerdifferent than that depicted herein, resulting in a component describedas above another component being vertically lower for those certainembodiments or resulting in a component described as to the rear ofanother being positioned forward of the other, depending on the frame ofreference of the observer. For example, an example transmission 100includes two countershafts (not shown) and a first particular featureengaging an upper countershaft may be described and depicted as above asecond particular feature engaging a lower countershaft; it isnevertheless contemplated herein that an arrangement with the firstparticular feature engaging the lower countershaft in the secondparticular feature engaging the upper countershaft is consistent with atleast certain embodiments of the present disclosure, except wherecontext indicates otherwise.

Referencing FIG. 2, a transmission 100 is depicted in a top view,wherein the transmission 100 depicted in FIG. 2 is consistent with thetransmission 100 depicted in FIG. 1. In the top view of the transmission100, the rear housing 108, the clutch housing 104, and the main housing102 remain visible. Additionally, the integrated actuator housing 112and TCM 114 are visible at the top of the main housing 102. The exampletransmission 100 further includes a clutch actuator housing 202 thatprovides accommodation for a clutch actuator assembly (not shown in FIG.2). Clutch actuator housing 202 is depicted as a portion of theintegrated actuator housing 112 and positioned at the top of thetransmission 100. The example clutch actuator housing 202 and clutchactuator assembly, as evidenced by the position of the clutch actuatorhousing 202, engages an upper countershaft at the rear side; however, alubrication pump assembly may engage one or more countershafts at anyaxial position along the transmission 100. Further details of an examplelubrication pump assembly are described in other portions of the presentdisclosure.

The example transmission 100 of FIG. 2 further depicts the output shaftassembly 110 at a rear of the transmission, in the example depicted as astandard driveline output shaft assembly 110; however, any output shaftassembly 110 design for the particular application is contemplatedherein. The transmission 100 further depicts an input shaft 204, in theexample the input shaft 204 extends through the clutch 106 on theoutside of the transmission 100, in engages a prime mover shaft, such astail shaft. An example input shaft 204 includes a spline engagement witha prime mover shaft, although any coupling arrangement understood in theart is contemplated herein.

The example transmission 100 depicted in FIG. 2 includes a single airinput line (not shown), which in the example is pneumatically coupled tothe integrated actuator housing 112. In certain embodiments, thetransmission 100 includes a clutch actuator and one or more shiftactuators, wherein the clutch actuator and the shift actuator(s) arepowered by a single or common air input supply line as depicted in theexample of FIG. 2. Additionally or alternatively, each of the actuatorsmay be powered by separate power inputs, and/or alternative powersources, such as, but not limited to, a hydraulic and/or an electricsource.

Referencing FIG. 3, a transmission 100 arranged in a similar orientationto the representation depicted in FIG. 1 is illustrated to more clearlyshow certain aspects of the transmission 100. The example transmission100 includes the integrated actuator housing 112, wherein an air inputport 302 provides pneumatic access for the air input supply to engagethe clutch actuator and the shift actuator(s). The example transmission100 includes only a single power input to operate all actuators, and infurther embodiments the single power input is included as an air inputport 302. In embodiments, a single air supply is provided for pneumaticactuation of the clutch actuator (such as a linear clutch actuator (LCA)and each of the gear shift actuators (e.g., actuators for front, mainand rear gear boxes). In embodiments, the air supply is handled withinthe integrated actuator housing via a set of conduits that accept airfrom the air input supply and deliver the air to power movement of eachof the actuators. The conduits may be integrated (e.g., machined, cast,etc.) into the housing/structure of the integrated actuator housing,such that air is delivered without requiring separate hoses or the like,between the air input supply and the respective actuators for clutch andgear movement. Among other benefits, this removes potential points offailure (such as leaky hoses or poor connections to hoses) and allowsvery precise control (because, among other reasons, the volume of air issmaller and more precisely defined that for a hose-based system). Itshould be understood that a given integrated actuator housing 112includes the number and type of power access points for the particulararrangement, such as an electrical and/or hydraulic input, and/or morethan one input of a given type, such as pneumatic Additionally oralternatively, in certain embodiments the transmission 100 includes oneor more power inputs positioned in locations distinct from the locationof the air input port 302 in the example of FIG. 4.

The example transmission 100 depicted in FIG. 3 further shows a sensorport 304. In the example of FIG. 3, sensor port 304 couples a controlleron the TCM 114 to a speed sensor on the output shaft assembly 110 of thetransmission 100. Referencing FIG. 4, a sensor coupler 404 operationallycouples a sensor (e.g. a speed sensor of any type, such as a halleffect, variable reluctance, tachograph, or the like) to the sensorconnector 304, for example to provide an output shaft speed value to theTCM 114. Additionally, the transmission 100 includes an oil pressuresensor 406. In embodiments, a given transmission 100 may include anynumber of sensors of any type desired, including having no speed sensorand/or other sensors. In certain embodiments, the type and source ofinformation may vary with the control features and diagnostics presentin the system. Additionally or alternatively, any given sensed value mayinstead be determined from other values known in the system (e.g. avirtual sensor, model, or other construction or derivation of a givenvalue from other sensors or other known information), and/or any givensensed value may be determined from a datalink communication oralternate source rather than or in addition to a direct sensor coupledto a controller. The controller may be in communication with any sensorand/or actuator anywhere on the transmission 100 and/or within a systemincluding or integrated with the transmission 100, such as a driveline,vehicle, or other application, as well as with remote systems, such asthrough one or more communications networks, such as Bluetooth™,cellular, WiFi, or the like, including to remote systems deployed in thecloud, such as for telematics and similar applications, among others.

The example transmission 100 includes a pair of electrical connectors402 (reference FIG. 4), depicted as two standard 20-pin connectors inthe example depicted in FIG. 4, although any electrical interface may beutilized. An example TCM 114 includes an electrical connection betweenthe TCM 114 and the integrated actuator housing 112, for example whereinthe TCM 114 plugs into the integrated actuator housing 112 providingelectrical datalink communication (e.g. between a controller present onthe integrated actuator and the controller on the TCM 114—not shown)and/or direct actuator control of actuators in the integrated actuatorhousing 112. In certain embodiments, a single controller may be presentwhich performs all operations on the transmission 100, and/or thefunctions of the transmission 100 may be divided among one or morecontrollers distinct from the controller arrangement depicted in FIG. 4.For example and without limitation, a vehicle controller, applicationcontroller, engine controller, or another controller present in thetransmission 100 or overall system may include one or more functions ofthe transmission 100.

The example transmission 100 further includes a clutch 106. The exampleclutch 106 includes a clutch face 306 and one or more torsional springs308. Example clutch face 306 includes a number of frictional plates 310,and the clutch face 306 presses against an opposing face from a primemover (not shown), for example a flywheel of the engine. The torsionalsprings 308 of the example clutch face 306 provide rotational damping ofthe clutch 106 to transient forces while maintaining steady statealignment of the clutch 106. The clutch face 306 may alternatively beany type of clutch face understood in the art, including for example asingle frictional surface rather than frictional plates 310. In theexample clutch face 306, the frictional plates 310 are included as aportion of the clutch face 306. The divisions between the clutch platesare provided as grooved divisions of the clutch face 306 base materialto provide desired performance (e.g. frictional performance, debrismanagement, and/or heat transfer functions), but any clutch face 306configuration including alternate groove patterns and/or no presence ofgrooves is contemplated herein. The material of the example clutch face306 may be any material understood in the art, including at least aceramic material and/or organic clutch material. In embodiments, asdepicted in more detail below, the clutch 106 may be positioned off-axisrelative to the prime mover, is disposed around (such as via a yoke,horseshoe or similar configuration) the prime mover (e.g., a shaft), ispivotably anchored on one side (such as by a hinge or similar mechanismthat allows it to pivot in the desired direction of movement of theclutch 106, and is actuated by the linear clutch actuator (which mayalso be positioned off-axis, opposite the anchoring side, so that linearactuation causes the clutch to pivot in the desired direction).

Referencing FIG. 4, an example transmission 100 is depicted from a sideview, with the output shaft assembly 110 positioned at the left side ofFIG. 4, in the clutch housing 104 positioned at the right side of FIG.4. The transmission 100 depicted in FIG. 4 includes numerous featuresthat may be present in certain embodiments. For example, numerous fins408 and/or projections are present that provide selected stresscharacteristics, management of stress in the housing, and or selectedheat transfer characteristics. The example transmission 100 furtherdepicts a power take off device (PTO) interface 410 that allows accessfor a PTO installation to engage the transmission on a lower side.Additionally or alternatively the transmission 100 may include a secondPTO interface on the rear of the transmission (not shown), for exampleto allow PTO engagement at the rear of the transmission 100. A rear PTOengagement may be provided with a hole (which may be plugged for anon-PTO installation) or other access facility, where the PTO may beengaged, for example, with a quill shaft engaging one of thecountershafts of the transmission 100 on a first end and providing anengagement surface, such as a spline, on a second end extending from thetransmission 100. The example transmission of FIG. 4 additionallydepicts a number of lift points 412, which are optionally present, andwhich may be arranged as shown or in any other arrangement or position.

Referencing FIG. 5, another view of an example transmission 100 isprovided depicting a clear view of the clutch actuator housing 202, theintegrated actuator housing 112, in the TCM 114. The exampletransmission 100 further includes a number of couplings 502 between themain housing 102 and a rear housing 108, and a number of couplings 504between the main housing 102 and the clutch housing 104. In certainembodiments the selection of housing elements (102, 104, 108) thatincludes the driveline portions of the transmission 100 may be distinctfrom the selection of housing elements (102, 104, 108) as depicted inFIG. 5. For example, certain housing elements may be combined, divided,and/or provided at distinct separation points from those depicted inFIG. 5. Several considerations that may be included in determining theselection of housing elements include the strength of materials utilizedin manufacturing housings, the power throughput of the transmission 100,the torque (maximum and/or transient) throughput of the transmission100, manufacturability considerations (including at least positioningthe housing and devices within the housing during manufacture, materialsselected for the housing, and/or manufacturing cost and repeatabilityconsiderations), and the cost and/or reliability concerns associatedwith each housing interface (for example the interface 506 between themain housing 102 and the rear housing 108).

Referencing FIG. 6, another view of an example transmission 100 isprovided depicting a clear view of the PTO interface 410. The examplePTO interface 410 is an 8 bolt interface provided on a lower side of thetransmission 100. Referencing FIG. 7 a schematic view of a transmissionhousing 700 is depicted. The housing 700 includes an actuator engagementopening 702 positioned at the top of the transmission. The actuatorengagement opening 702 is sized to accommodate attachment of theintegrated actuator housing 112, and to allow actuation elements to bepositioned into the transmission 100. The position, size, shape, andother elements of an actuator engagement opening 702, where present, maybe selected according to the particular features of actuators for thesystem. The example transmission 100, actuator engagement opening 702,and integrated actuator housing 112, are readily accessible with accessto the top of the transmission 100, and can be installed, serviced,maintained, or otherwise accessed or manipulated without removal of thetransmission 100 from the application or vehicle, and/or withoutdisassembly of the transmission 100. The example housing 700 furtherincludes a clutch actuator engagement opening 704, sized to accommodateattachment of the clutch housing portion of the integrated actuatorhousing 112, and to allow the clutch actuator to be positioned into thetransmission 100. In the example housing 700, shift actuators (notshown) are positioned into the transmission 100 through the actuatorengagement opening 702, and a clutch actuator is positioned into thetransmission 100 through the clutch actuator engagement opening 704, andit can be seen that a single step installation of the integratedactuator housing 112 provides an insulation of all primary actuators forthe transmission 100, as well as providing a convenient single locationfor access to all primary actuators.

Referencing FIG. 8, an example transmission 100 is depictedschematically in a cutaway view. The cutaway plane in the example ofFIG. 8 is a vertical plane through the transmission 100. The exampletransmission 100 is capable of providing power throughput from a primemover interfacing with the clutch 106 to the input shaft 204, from theinput shaft 204 to a first main shaft portion 804, to a second mainshaft portion 806 operationally coupled to the first main shaft portion804, and from the second main shaft portion 806 to the output shaftassembly 110. Example transmission 100 is operable to adjust torquemultiplication ratios throughout the transmission, to engage anddisengage the clutch 106 from the prime mover (not shown), and/or toposition the transmission 100 into a neutral position wherein, even ifthe clutch 106 is engaged to the prime mover, torque is not transmittedfrom the clutch 106 to the output shaft assembly 110.

With further reference to FIG. 8, a clutch engagement yoke 808 isdepicted in a first position 808A consistent with, in certainembodiments, the clutch 106 being engaged with the prime mover (i.e. theclutch 106 in a forward position). For purposes of clarity of thedescription, the clutch engagement yoke 808 is simultaneously depictedin a second position 808B consistent with, in certain embodiments, theclutch 106 being disengaged with the prime mover (i.e. the clutch 106 ina withdrawn position). The example clutch engagement yoke 808 isoperationally coupled at a first end to a clutch actuator, which in theexample of FIG. 8 engages the clutch engagement yoke at the upper end ofthe clutch engagement yoke 808. The example clutch engagement yoke 808is fixed at a second end, providing a pivot point for the clutchengagement yoke 808 to move between the first position 808A and thesecond position 808B. A clutch engagement yoke 808 of the example inFIG. 8 enables convenient actuation of the clutch 106 with a linearactuator, however in certain embodiments of the present disclosure anytype of clutch actuation may be utilized, including a concentric clutchactuator (not shown) and/or another type of linear clutch actuationdevice.

The example transmission 100 further includes an input shaft gear 810selectively coupled to the input shaft 204. The inclusion of the inputshaft gear 810, where present, allows for additional distinct gearratios provided by the input shaft 204, for example a gear ratio wheretorque is transmitted to the input shaft gear 810, where torque istransmitted directly to the first main shaft portion 804 (e.g. with boththe input shaft 204 and the first main shaft portion 804 coupled to afirst forward gear 812). In certain embodiments, the shared firstforward gear 812 between the input shaft 204 and the first main shaftportion 804 may be termed a “splitter gear,” although any specificnaming convention for the first forward gear 812 is not limiting to thepresent disclosure.

The example transmission 100 further includes a number of gearsselectively coupled to the first main shaft portion 804. In the exampleof FIG. 8, the first forward gear 812, a second forward gear 814, andthird forward gear 816 are depicted, and a first reverse gear 818 isfurther shown. In the example, the first forward gear 812 is couplableto either of the input shaft 204 and/or the first main shaft portion804. When the input shaft 204 is coupled to the first forward gear 812and the first main shaft portion 804 is not, a gear ratio between theinput shaft 204 and the first main shaft portion 804 is provided. Whenthe input shaft 204 is coupled to the first forward gear 812 and thefirst main shaft portion 804 is also coupled to the first forward gear812, the input shaft 204 and first main shaft portion 804 turn at thesame angular speed. The number and selection of gears depends upon thedesired number of gear ratios from the transmission, and the depictednumber of gears is not limiting to the present disclosure.

The example transmission 100 further includes a planetary gear assembly820 that couples the second main shaft portion 806 to the output shaftassembly 110 through at least two selectable gear ratios between thesecond main shaft portion 806 and the output shaft assembly 110. Theexample transmission 100 further includes at least one countershaft, thecountershaft having an aligning gear with each of the gears coupleableto the input shaft 204 in the first main shaft portion 804. Thecountershaft(s) thereby selectively transmit power between the inputshaft 204 in the first main shaft portion 804, depending upon whichgears are rotationally fixed to the input shaft 204 and/or the firstmain shaft portion 804. Further details of the countershaft(s) aredescribed following, for example in the portion of the disclosurereferencing FIG. 9.

It can be seen that the transmission 100 in the example of FIG. 8provides for up to 12 forward gear ratios (2×3×2) and up to four reversegear ratios (2×1×2). A particular embodiment may include distinct geararrangements from those depicted, and/or may not use all available gearratios. In embodiments, an eighteen speed automatic truck transmissionmay be provided, such as by providing three forward gears, three maingears, and two planetary gears, referred to herein as athree-by-three-by-two architecture. Similarly, a twelve-speed automatictruck transmission can be provided by providing three forward gears, twomain gears, and two planetary gears, or other combinations.

Referencing FIG. 9, an example transmission 100 is depictedschematically in a cutaway view. The example of FIG. 9 depicts a cutawaythrough a plane intersecting to twin countershafts 902, 904. The examplecountershafts 902, 904 are positioned at 180° on each side of the firstmain shaft portion 804. In certain embodiments the transmission 100 mayinclude only a single countershaft, and/or more than two countershafts.The positioning and angle of the countershafts 902, 904 depicted in FIG.9 is a nonlimiting example, and the countershafts 902, 904 may beadjusted as desired for the application. Each of the examplecountershafts 902, 904 includes a gear layer 906 meshing with acorresponding gear on the input shaft 204 and/or the first main shaftportion 804 respectively. The example transmission 100 includes thegears 906 rotationally fixed to the countershafts 902, 904, with thecorresponding gears on the input shaft 204 and/or the first main shaftportion 804 being selectively rotationally fixed to the input shaft 204and/or the first main shaft portion 804. Additionally or alternatively,gears 906 may be selectively rotationally fixed to the countershafts902, 904, with one or more of the corresponding gears on the input shaft204 and/or the first main shaft portion 804 being rotationally fixed tothe input shaft 204 and/or the first main shaft portion 804. Thedescriptions of actuators for shifting presented herein utilize theconvention that the gears 906 are rotationally fixed to thecountershafts 902, 904, and changes to which gears are rotationallyfixed or selectively rotationally fixed would lead to correspondingchanges in actuation.

Example transmission 100 includes a first actuator 908, for example ashift fork, that moves (e.g., side to side and/or up or down) underactuation, to selectively rotationally couple the input shaft 204 to oneof the countershafts 902, 904, or to the first main shaft portion 804.The first actuator 908 interacts with a gear coupler 910, and in certainembodiments the gear coupler 910 includes a synchronizing component asunderstood in the art. The first actuator 908 is further operable toposition the gear coupler 910 into an intermediate position wherein theinput shaft 204 is rotationally decoupled from both the countershafts902, 904 and the first main shaft portion 804—for example placing thetransmission 100 into a neutral operating state. In certain embodimentsthe first actuator 908 is a portion of, and is controlled by anintegrated actuator assembly 1300 (e.g. reference FIG. 13) positionedwithin the integrated actuator housing 112.

Example transmission 100 further includes a second actuator 912 that,under actuation, such as moving side to side and/or up or down,selectively rotationally couples one of the first forward gear 812 andthe second forward gear 814 to the first main shaft portion 804, therebyrotationally coupling the countershafts 902, 904 to the first main shaftportion 804. The example transmission 100 further includes a thirdactuator 914 that, under actuation, selectively rotationally couples oneof the third forward gear 816 and the reverse gear 818 to the first mainshaft portion 804, thereby rotationally coupling countershafts 902, 904to the first main shaft portion 804. In certain embodiments, the secondactuator 912 in the third actuator 914 are operable to be positionedinto an intermediate position wherein the first main shaft portion 804is rotationally decoupled from both the countershafts 902, 904—forexample placing the transmission 100 into a neutral operating state. Incertain embodiments, at least one of the second actuator 912 and thethird actuator 914 are positioned into the intermediate position at anygiven time, preventing coupling of the countershafts 902, 904 to thefirst main shaft portion 804 at two different speed ratiossimultaneously. In certain embodiments the second actuator 912 and thethird actuator 914 are portions of or are integrated with, and arecontrolled by, the integrated actuator assembly 1300 positioned withinthe integrated actuator housing 112.

In the example transmission 100, the second actuator 912 interacts witha second gear coupler 916, and the third actuator 914 interacts with athird gear coupler 918, where each of the second and third gear couplers916, 918 may include a synchronizing component. According to thearrangement depicted in FIG. 9, the first, second, and third actuators908, 912, 914 are operable to provide a number of distinct forward gearoptions, reflecting different combinations of gear ratios (e.g., six,twelve, or eighteen gears), and a number (e.g., two) of distinct reversegear ratios. The planetary gear assembly 820 may include a clutch (suchas a sliding clutch 920) configured to position the planetary gearassembly 820 and provide two distinct ratios between the second mainshaft portion 806, and the output shaft assembly 110. Therefore,according to the arrangement depicted in FIG. 9, the transmission 100 isoperable to provide twelve distinct forward gear ratios, and fourdistinct reverse gear ratios. In certain embodiments, one or more of theavailable gear ratios may not be utilized, and a selection of the numberof forward gears, number of reverse gears, and number of actuators maybe distinct from the arrangement depicted in FIG. 9.

The example transmission 100 provides for a direct drive arrangement,for example where the first actuator 908 couples the input shaft 204 tothe first main shaft portion 804 (gear coupler 910 to the right in theorientation depicted in FIG. 9), and where the second actuator 912couples the first main shaft portion 804 the first forward gear. Directdrive operation transfers power through the planetary gear assembly 820,with the sliding clutch 920 providing either gear reduction (e.g.sliding clutch 920 positioned to the right in the orientation depictedin FIG. 9) or full direct drive of the transmission 100 (e.g. slidingclutch 920 positioned to the left in the orientation depicted in FIG.9). In certain embodiments, direct drive may be a “highest” gear ratioof the transmission 100, and/or the transmission may include one or moreoverdrive gears. The determination of the number of gears, how manygears are forward and/or reverse, and the ratios of each gear, includingwhether and how many overdrive gears may be present, and how many gearratio combinations are selectable, are configurable features that dependupon desired response characteristics for a particular application. Anexample transmission 100 includes the integrated actuator assembly 1300operably coupled to the sliding clutch 920, for example with a shiftfork (not shown) mounted on a shift rail.

The example transmission 100 depicts the PTO interface 410 positioned inproximity to the lower countershaft 904. In certain embodiments, thetransmission 100 includes a main housing 102 where the main housing 102is made of aluminum, and/or is a cast component. It will be understoodthat material constraints and component stress management indicate thatcertain features of an aluminum housing will be larger, thicker, orotherwise modified relative to a steel housing. For example bolt bossesof the PTO interface 410 can be deeper and project further into the mainhousing 102 for a PTO interface 410 designed in an aluminum housingrelative to a similar installation designed in a steel housing. Castcomponents, in certain embodiments and depending upon casting processused, impose certain constraints upon component design. For example, forcertain casting processes it can be beneficial to constrain a componentto have a monotonically increasing outer profile or housing shape.Example transmission 100 includes gear ratio and sizing selections, aswell as selection of the PTO interface 410 position, such that a gear ofthe lower countershaft 904 having a greatest radial extent from acenterline the gear train is positioned in proximity to the PTOinterface 410. An example transmission 100 includes the PTO deviceaccessing the transmission 100 at the PTO interface 410 being powered bythe first forward gear 812 (e.g. the splitter gear) through thecorresponding countershaft gear.

In certain embodiments, the transmission 100 allows for engagement of aPTO device (not shown) directly with a gear engaging in lowercountershaft 904, without having to use in idler gear or similarmechanical configuration to extend power transfer from the lowercountershaft 904. It can also be seen that the example transmission 100includes a geometric profile of the gears in the gear train, such thatan easily castable main housing 102 can be positioned over the gearsafter the gear train is assembled, and/or the gear train can beassembled into the main housing 102 in a straightforward manner.Further, it can be seen that the example transmission 100 includesprovisioning for bolt bosses of the PTO interface 410, even where deeperbolt bosses are provided, such as an application having an aluminum mainhousing 102.

Example transmission 100 further includes a controllable braking device922 selectively coupleable to at least one of the countershafts 902,904. In the example depicted in FIG. 9, the braking device 922 isselectively coupleable to the lower countershaft 904, however a brakingdevice 922 may be coupleable to either countershaft 902, 904, and/ormore than one braking device may be present in coupleable to eachcountershaft present. The braking device 922 provides capability to slowthe countershaft and/or driveline, to stop the countershaft and/ordriveline, and/or to provide stationary hold capability to thedriveline. An example braking device 922 includes a braking deviceactuator 924 (a pneumatic input in the example of FIG. 9) which may becontrollable pneumatically by an integrated actuator assembly 1300positioned in the integrated actuator housing 112. Additionally oralternatively, any other actuating means and controller is contemplatedherein, including at least an electrical and/or hydraulically operatedactuator, and/or any other driveline braking device, is furthercontemplated herein. Additionally or alternatively, any other type ofbraking device may be included within the transmission 100 and/orpositioned upstream or downstream of the transmission 100, for example ahydraulic retarder and/or an electric braking device (not shown), whichmay be controllable by an actuator in the integrated actuator assembly1300 positioned in the integrated actuator housing 112, by the TCM 114,and/or by another control device in the system (not shown).

The example transmission 100 includes the output shaft assembly 110. Theexample output shaft assembly 110 includes an output shaft 926, whereinthe output shaft is rotationally coupled to the planetary gear assembly820. The output shaft assembly 110 further includes a driveline adapter928 coupled to the output shaft 926, and configured to engage adownstream device (not shown) in the driveline. The driveline adapter928 may be any type of device known in the art, and the specificdepiction of the driveline adapter 928 is nonlimiting. The selection ofa driveline adapter 928 will depend in part on the application, the typeof downstream device, and other considerations known in the art.

Referencing FIG. 10, an example transmission 100 is depictedschematically in a cutaway view. The cutaway plane and the example ofFIG. 10 is a plane intersecting a clutch actuator 1002 in the driveline(e.g. including the input shaft four, the first and second main shaftportions 804, 806, in the output shaft assembly 110). The depiction inFIG. 10 illustrates the clutch engagement yoke 808 in both the firstposition 808A in the second position 808B. The example transmission 100includes a linear clutch actuator 1002, positioned within the clutchactuator housing 202 and extending to the clutch engagement yoke 808. Inthe example of FIG. 10, the clutch actuator 1002 is pneumaticallyoperated and applies a pushing force to the clutch engagement yoke 808,and returns a retracted position in response to force from the clutchengagement yoke 808. Example clutch actuator 1002 provides a normallyengaged clutch 106, such that if the clutch actuator 1002 is notactively engaging the clutch engagement yoke 808, the clutch 106 extendsand engages. The example clutch actuator 1002 is a pneumatic, linearclutch actuator (LCA), that pushes to engage, however any type of clutchactuator is contemplated herein, for example and without limitation apull to engage actuator (e.g. utilizing a catapult or other mechanicalarrangement), hydraulic and/or electrical actuation, and/or engagingwith a normally engaged or normally disengaged clutch 106. In certainembodiments, the clutch actuator 1002 includes a near zero dead airvolume in the retracted position. Example support features to maintainnear zero dead air volume for the clutch actuator 1002 are described asfollows. In certain embodiments, the utilization of a linear actuator,the inclusion of a near zero dead air volume, and the positioning of theclutch actuator housing 202 as a part of the integrated actuator housing112 support various enhancements of one or more of accessibility to theclutch actuator housing 202, accessibility to the clutch actuator 1002,improvements to the control and/or repeatability of clutch actuation,reduction of points of failure, and/or diagnosing or determining theprecise position of the clutch face 306 (including as the clutch 106wears over time). In certain embodiments, a near zero dead air volumeincludes a volume 1004 behind the clutch actuator 1002 on a supply side,wherein the volume 1004 is small enough such that provided airimmediately begins putting an actuation force onto the clutch actuator1002, and/or such that a consistent initial air volume each times beginsa consistent movement on the clutch actuator 1002. Example air volumesthat are near zero include, without limitation, the clutch actuator 1002positioned against an air feed tube (e.g. as depicted in the example ofFIG. 10), a volume small enough such that clutch actuation begins afterapplication of supply pressure within a selected response time (e.g. 5msec, 10 msec, 20 msec, 40 msec, 100 msec, and/or 200 msec), and/or avolume less than a specified volume difference behind the clutchactuator 1002 on the feed side between the clutch actuator 1002 in acurrent rest position and the clutch actuator 1002 in a predeterminedrest position (e.g. fully positioned against a stop), where thespecified volume is approximately zero, less than 0.1 cc, less than 0.5cc, and/or less than 1 cc. The provided examples for a near zero volumeare illustrative and not limiting. One of skill in the art, having thebenefit of the present disclosure and information ordinarily availablewhen contemplating a particular embodiment, can readily determine a nearzero volume for a contemplated application. Certain considerations todetermine a near zero dead air volume include, without limitation, thepressure and/or rate of supplied actuation air, the desired responsetime for the clutch actuator 1002, computing resources available on theTCM 114 or elsewhere in the system, and/or the physical responsivenessof the clutch actuator 1002 to supplied air.

The example transmission 100 depicted in FIG. 10 includes a first ballbearing 1102 positioned in the clutch housing 104 (and/or pressed intothe clutch housing 104) and coupled to the input shaft 204, a secondball bearing 1104 positioned in the main housing 102 (and/or pressedinto the main housing 102) and coupled to the second main shaft portion806, and a third ball bearing 1106 positioned in front of the planetarygear assembly 820 and coupled to the second main shaft portion 806.Additionally or alternatively, the example transmission 100 includes afourth ball bearing 1109 positioned at an interface between the rearhousing 108 and the output shaft assembly 110 (e.g. pressed into therear housing 108), and coupled to the output shaft 926. An exampletransmission 100 further includes a release bearing 1118 coupled to theclutch 106 and providing a portion of an assembly between the clutchengagement yoke 808 and a clutch assembly to provide for release of theclutch 106 in response to actuation of the clutch engagement yoke 808.

Referencing FIG. 11, certain elements of an example housing assembly1100 are depicted schematically and in exploded view. The examplehousing assembly 1100 depicts the clutch housing 104, the main housing102, and the rear housing 108. Example housing assembly 1100 includesthe first ball bearing 1102 positioned in the clutch housing 104 andengaging the input shaft 204, the second ball bearing 1104 positioned inthe main housing 102 and engaging the second main shaft portion 806, andthe fourth ball bearing 1109 positioned in the rear housing 108 andengaging the output shaft 926 at an interface between the rear housing108 and the output shaft assembly 110. The ball bearings 1102, 1104, and1109 provide for robust alignment of the transmission driveline, forexample to ensure alignment with upstream and downstream drivelinecomponents. Additionally or alternatively, the ball bearings 1102, 1104,and 1109 are pressed into respective housing elements to provide forease of manufacture and/or assembly of the transmission 100. The numberand arrangement of ball bearings in a particular transmission 100 is adesign choice, and any provided number and arrangement of ball bearingsis contemplated herein.

The example housing assembly 1100 further includes a number of rollerbearings 1108, which may be pressed into respective housing elements, inthe example a roller bearing engages each end of the countershafts 902,904. In a further example, a forward end of the countershafts 902, 904each engages one of the roller bearings 1108 at an interface between theclutch housing 104 and the main housing 102, and a rearward end of thecountershafts 902, 904 each engages one of the roller bearings 1108 atan interface between the main housing 102 in the rear housing 108. Thetype, number, and location of bearings engaging the countershafts 902,904 are design choices, and any provided number, type, and location ofbearings are contemplated herein.

In embodiments, one or more bearings, including for various gears of thetransmission, may be configured to reduce or cancel thrust loads thatoccur when the drive shaft for the vehicle is engaged.

Example housing assembly 1100 further includes a cover plate 1110 forthe PTO interface 410, and associated fasteners 1112 (e.g. bolts in theexample housing assembly 1100). A cover plate 1110 may be utilized wherea PTO device does not engage PTO interface 410, such as where no PTOdevice is present and/or where a PTO device engages a transmission froma rear location or other location. In certain embodiments, for examplewhere transmission 100 does not include the PTO interface 410, the coverplate 1110 may be omitted. Additionally or alternatively, thetransmission 100 included in a system planned to have a PTO deviceengaging the PTO interface 410 may likewise omit the cover plate 1110,and/or include a cover plate 1110 that is removed by an originalequipment manufacturer (OEM) or other installer of a PTO device.

The example housing assembly 1100 further includes a bearing cover 1114,where the bearing cover 1114 protects and retains the fourth ballbearing 1109. Additionally, in certain embodiments, the example housingassembly 1100 further includes a seal 1116, for example to retainlubricating oil for the output shaft 926 and/or the fourth ball bearing1109 within the transmission 100. The presence and type of seal 1116depend upon the characteristics and type of lubrication system, and maybe of any type.

Referencing FIG. 12, an exploded view 1200 of portions of an open clutchhousing 104 consistent with certain embodiments of the presentdisclosure is schematically depicted. The view 1200 depicts a firstcover 1202 corresponding to, in the example, the upper countershaft 902.The view 1200 further depicts a first cover seal 1204, wherein the firstcover seal 1204 provides for sealing between the first cover 1202 andthe clutch housing 104. The view 1200 further depicts a braking device922 in exploded view. The example braking device 922 includes a brakingdisc assembly 1206. The example braking device 922 includes a brakingdevice actuator 924 depicted as a portion thereof. The example brakingdevice actuator 924 includes a braking piston 1208, piston seals 1210, apiston wear ring 1212, and a braking cover seal 1214. The examplebraking cover seal 1214 includes an actuation control input 1216, forexample a pneumatic port coupled to the integrated actuator assembly1300 positioned in the integrated actuator housing 112, such as throughan air tubing 1226. Any type of actuation coupling, and/or control arecontemplated herein, including at least hydraulic and/or electricalactuation. In certain embodiments, the piston seals 1210 and pistonwearing 1212 are positioned in grooves 1218 provided along a bore of thebraking piston 1208. The view 1200 further depicts a second cover seal1220 and a third cover seal 1222, as well as a braking cover adapter1224. In the example of the view 1200, the second cover seal 1220provides sealing between the braking cover adapter 1224 and the clutchhousing 104, and the third cover seal 1222 provides sealing between thebraking cover adapter 1224 and the braking cover seal 1214.

Referencing FIG. 13, an example integrated actuator assembly 1300includes an integrated actuator housing 112 and a clutch actuatorhousing 202. The example integrated actuator assembly 1300 depicts anexample first actuator 908 operationally coupled to a first shift rail1302 (e.g. a pneumatic rail), an example second actuator 912 coupled toa second shift rail 1304, and an example third actuator 914 coupled to athird shift rail 1306. The shape, position, and shift rail positions ofthe actuators 908, 912, 914 are selectable to meet the geometry,actuation force requirements, and the like of a particular application.The example integrated actuator assembly 1300 further includes theclutch actuator 1002 positioned in the clutch actuator housing 202 andoperationally coupled to the integrated actuator assembly 1300. The TCM114 is depicted as mounted on the integrated actuator assembly 1300,although the TCM 114 may be positioned elsewhere in a particulartransmission 100. A seal 1308 is provided between the integratedactuator housing 112 and the TCM 114 in the example arrangement.Additional actuation engagement points 1310, 1312 are provided, forexample to operationally couple the sliding clutch 920 and/or theactuator control input 1216 to the integrated actuator assembly 1300.The position and arrangement of additional actuation engagement points1310 are non-limiting and may be arranged in any manner. The arrangementdepicted in FIG. 13 allows for centralized actuation of active elementsof a transmission 100, while allowing ready access to all actuators forinstallation, service, maintenance, or other purposes.

Referencing FIG. 14, a topside view of the integrated actuator assembly1300 is provided. The integrated actuator assembly 1300 depicts a TCMcover 1402, which protects and engages the TCM 114 to the integratedactuator housing 112. A connector 1404 is depicted between the TCM 114and the integrated actuator housing, with a TCM connector seal 1406 alsoprovided. The arrangement and engagement of the TCM 114 is anon-limiting example. Referencing FIG. 15, another view of the exampleintegrated actuator assembly 1300 is shown to provide another angle toview details of the assembly. In certain embodiments, all shift rails1302, 1304, 1306, the clutch actuator 1002, and the additional actuationengagement points 1310, 1312 are operated from a single power sourcecoupled to the transmission 100 from the surrounding system orapplication, and in a further example coupled to a single air powersource. The selection of a power source, including the power source type(e.g. pneumatic, electrical, and/or hydraulic) as well as the number ofpower sources, may be distinct from those depicted in the example. Incertain embodiments, additional shift rails and/or actuators may bepresent, for example to provide for additional gear shifting operationsand/or to actuate other devices.

Referencing FIG. 16, an example lubrication pump assembly 1600 isdepicted. The example lubrication pump assembly 1600 is positionedin-line within the transmission rear housing 108 and against theinterface to the main housing 102. The lubrication pump assembly 1600defines a first hole 1602 therein to accommodate the main drivelinepassing therethrough, a second hole 1604 therein to accommodate acountershaft (the upper countershaft 902 in the example), and includes acountershaft interface assembly 1606 that engages one of thecountershafts (the lower countershaft 904 in the example). Thelubrication pump assembly draws from an oil sump 1608 at the bottom ofthe transmission 100. In the example transmission 100, the oil sump 1608is a dry sump—for example the gears and rotating portions of thetransmission do not rotate within the oil in the sump. One of skill inthe art will recognize that maintaining a dry sump reduces the losses inrotating elements, as they are rotating in air rather than a viscousfluid, but increases the challenges in ensuring that moving parts withinthe transmission maintain proper lubrication. Oil may drain to the sump1608 and be drawn from the sump by the lubrication pump assembly 1600.In certain embodiments, the sump 1608 is positioned in the rear housing108, but may be positioned in the main housing 102 (e.g. with thelubrication pump assembly 1600 positioned within the main housing,and/or fluidly coupled to the main housing), and/or both housings 108,102, for example with a fluid connection between the housings 108, 102.

Referencing FIG. 17, an example lubrication pump assembly 1600 isdepicted in exploded view. The example lubrication pump assembly 1600includes a lubrication pump housing 1702 that couples the lubricationpump assembly 1600 to the transmission 100, and provides structure andcertain flow passages to the lubrication pump assembly. The examplelubrication pump assembly 1600 further includes a pump element 1704, inthe example provided as a gear pump, and a relief valve provided as acheck ball 1706, a biasing member 1708, and a plug 1710 retaining therelief valve. The lubrication pump assembly 1600 further includes adriving element 1712 that couples the pump element 1704 to the engagedcountershaft. Additionally, the example lubrication pump assembly 1600includes a spacer 1714 and a lubrication driveline seal 1716. Theexample lubrication pump includes an oil pickup screen 1718 and a screenretainer 1720. The arrangement of the example lubrication pump assembly1600 provides for an active lubrication system driven from acountershaft, which operates from a dry sump and includes pressurerelief. The arrangement, position, pump type, and other aspects of theexample lubrication pump assembly 1600 are non-limiting examples.

Referencing FIG. 18, an example transmission 100 is depicted. Theexample transmission 100 includes lubrication tubes provided thereinthat route lubrication from the lubrication pump assembly 1600 to movingparts within the transmission 100. The first lubrication tube 1802 isdepicted schematically to provide a reference for the approximateposition within the transmission 100 where a first lubrication tube 1802is positioned. The second lubrication tube 1804 is depictedschematically to provide a reference for the approximate position withinthe transmission 100 where a second lubrication tube 1804 is positioned.The actual shape, position, and routing of any lubrication tubes 1802,1804 within a given transmission will depend upon the location andarrangement of the lubrication pump assembly 1600, the parts to belubricated, the shape and size of the transmission housing elements, andthe like. Accordingly, the first lubrication tube 1802 and secondlubrication tube 1804 depicted herein are non-limiting examples oflubrication tube arrangements.

Referencing FIG. 19, the first lubrication tube 1802 is depicted in atop view and in a bottom view (reference FIG. 20). Referencing FIG. 21,a second lubrication tube 1804 is depicted in a side view and a top view(reference FIG. 22). The lubrication tubes 1802, 1804 provide forlubrication to all bearings, sleeves, and other elements of thetransmission 100 requiring lubrication, and contribute to a lubricationsystem having a centralized lubrication pump assembly 1600 with shortlubrication runs, no external hoses to support the lubrication system,and low lubrication pump losses.

Referencing FIG. 23, an example main driveline assembly 2102 is depictedschematically, with an angled cutaway view to illustrate certainportions of the main driveline. The main driveline assembly 2102includes the input shaft 204, the first mainshaft portion 804, thesecond mainshaft portion 806, and the output shaft 926. The maindriveline assembly 2102 further includes an upper countershaft 902 and alower countershaft 904. In the example of FIG. 23, the lowercountershaft 904 engages a braking device (e.g. reference FIG. 12) at aforward end, and a lubrication pump device (e.g. reference FIGS. 16 and17) at a second end. The main driveline assembly 2102 further includesthe planetary gear assembly 820 and the driveline adapter 928. Theexample main driveline assembly 2102 includes helical gears on the mainpower transfer path—for example on the countershaft, input shaft, andfirst mainshaft portion gears.

Referencing FIG. 24, an example main driveline assembly 2102 is depictedschematically, with no cutaway on the assembly. The planetary gearassembly 820 in the example includes a ring gear 2202 coupled to theoutput shaft 926. The sliding clutch 920 engages a sun gear withplanetary gears, changing the gear ratio of the planetary gear assembly820. Additionally in the view of FIG. 24, an idler gear 2204 couples oneor both countershafts 902, 904 to the reverse gear 818. The maindriveline assembly 2102 as depicted in FIGS. 23 and 24 is a non-limitingillustration of an example driveline assembly, and other arrangementsare contemplated herein. It can be seen in the example arrangement ofFIGS. 21 and 22 that torque transfer throughout the transmission 100occurs across helical gears, is shared between two countershaftsreducing the torque loads on each countershaft, and provides for aprojecting gear 2206 that extends radially outward at a greater extentfrom the countershaft 904 to facilitate radial engagement of PTO device.The example arrangement can be seen to be readily manufacturable withina cast housing. Additional features and/or benefits of an example maindriveline assembly 2102 are described throughout the presentspecification. A given embodiment may have certain ones of the examplefeatures and benefits. Referencing FIG. 25, an example main drivelineassembly 2102 is depicted schematically in a cutaway view. In certainembodiments, the main driveline assembly 2102 is consistent with otherdepictions of an example transmission, and the view of FIG. 25 providesa different view of the main driveline assembly 2102 to furtherilluminate example details.

Referencing FIG. 26, an example input shaft assembly 2400 is depicted incutaway view. The example input shaft assembly 2400 includes a snap ring2402 that retains the first ball bearing 1102. The example input shaftassembly 2400 further depicts a first synchronizer ring 2404 thatengages an input shaft gear 810, and a second synchronizer ring 2406that engages a first forward gear 812. It can be seen in the example ofFIG. 26 that engagement with the input shaft gear 810 rotationallycouples the input shaft 204 to the countershafts 902, 904, andengagement with the first forward gear 812 couples the input shaft 204to the first mainshaft portion 804 (e.g. when the first main shaftportion 804 is also coupled to the first forward gear 812) and/or thecountershafts (e.g. when the first mainshaft portion 804 is notrotationally coupled to the first forward gear 812). The example inputshaft assembly 2400 further includes a thrust bearing 2408, a thrustbearing washer 2410, and a roller needle bearing 2412. The example inputshaft assembly 2400 does not include any taper bearings.

Referencing FIG. 27, a close up view of an example first actuator 908assembly 2500 is depicted schematically. The example assembly 2500includes a synchronizer roller 2502 and the first and secondsynchronizer rings 2404, 2406. A synchronizer biasing member 2504 andsynchronizer plunger 2506 position the synchronizer roller 2502 relativeto the first actuator 908, while allowing flexibility during movementcaused by shifting operations.

Referencing FIG. 28, an example first end 2600 of the input shaft 204 isdepicted, which in the example of FIG. 28 is the end of the input shaft204 positioned toward the prime mover. The example end 2600 includes ajournal bearing 2602, with a coiled pin 2604 or similar fastener and asnap ring 2606 cooperating to ensure a desired position of the journalbearing 2602 is maintained. The example features of the input shaft 204are a non-limiting example, and other configurations at the first end2600 of the input shaft are contemplated herein. The outer surface 2608of at least a portion of the input shaft 204 is splined, for example torotationally engage the clutch 106 to the input shaft, therebytransferring torque from a prime mover output (e.g. a flywheel) to theinput shaft 204.

Referencing FIG. 29, an example first main shaft portion assembly 2700is depicted. In certain embodiments, the first main shaft portion 804may be termed “the main shaft,” the second main shaft portion 806 may betermed a “sun gear shaft” or similar term, and the output shaft assembly110 including the output shaft 926 and driveline adapter 928 may betermed collectively the “output shaft.” The naming convention utilizedfor parts in the transmission 100 is not limiting to the presentdisclosure, and any naming of parts performing various functionsdescribed herein is contemplated within the present disclosure. Theexample first main shaft portion assembly 2700 includes a seal 2702,which may be a cup seal, positioned within the first main shaft portion804 to at least partially seal lubricating oil in the first main shaftportion 804. The example first main shaft portion assembly 2700 furtherincludes the gears 812, 814, 816, 818 selectively coupled to the mainshaft portion 804. The naming of gears herein—for example the firstforward gear 812, is not related to the “gear” the transmission 100 isoperating in—for example “first gear.” The gear the transmission 100operates in is determined by design according to the desired finaloutput ratios of the transmission 100, and the transmission 100operating in first gear may imply a number of gear connections withinthe transmission 100 to provide the implementation of an operational“first gear” for a vehicle or other application. Typically, gearprogression occurs from a first gear to a highest gear, with the firstgear providing the highest torque amplification (e.g. prime mover torquemultiplied by the total gear ratio experienced at the output shaft 926,and/or further adjusted downstream of the transmission 100 before theload, such as at a rear axle), and the highest gear providing the lowesttorque amplification (including an “amplification” ratio less than 1:1,for example in an overdrive gear). Any arrangement of gears and gearprogressions are contemplated herein, and not limiting to the presentdisclosure. In certain embodiments, the transmission 100 operates indirect drive (e.g. all shafts 204, 804, 926 spinning at the same speed)and/or in partial direct drive operation (e.g. shafts 204, 804 spinningat the same speed, and shaft 926 having gear reduction from theplanetary gear assembly 820).

The example first main shaft portion assembly 2700 further includes amainshaft key 2704, which may be utilized, for example, to ensurealignment and/or positioning of the first main shaft portion 804. Anexample first main shaft portion assembly 2700 further includes a mainshaft thrust bearing 2706 configured to accept thrust loads on the firstmain shaft portion 804, and a race bearing 2708 configured to acceptradial loads on the first main shaft portion 804. In certainembodiments, the first main shaft portion assembly 2700 does not includeany taper bearings. An example first main shaft portion assembly 2700includes a main shaft snap ring 2710 and a thrust washer 2712, whichcooperate to retain the bearings 2706 and 2708. The second actuator 912and third actuator 914 (sliding clutches in the example of FIG. 29) areoperated by shift forks from the integrated actuator assembly 1300 toprovide for gear selection on the first main shaft portion 804. Theexample first main shaft portion assembly 2700 further includes asynchronizer flange 2714 utilized, in certain embodiments, to couple theinput shaft 204 with the first forward gear 812 and/or first main shaftportion 804.

Referencing FIG. 30, an example countershaft 904, the lower countershaftin certain examples of the transmission 100, is depicted in a detailedview. The example countershaft 904 includes the gears 906 that arerotationally fixed, in certain embodiments, to the countershaft 904, andthat mesh with the gears of the first main shaft portion 804 and/orinput shaft 204. The example countershaft 904 includes a firstengagement feature 2802 at a first end for interfacing with a frictionbrake. In certain embodiments, the friction brake may be termed an“inertia brake,” “inertial brake,” or the like, although the presentdisclosure is not limiting to any terminology or type of brake exceptwhere context specifically indicates. The friction brake may be any typeof braking mechanism known in the art, including at least anelectro-magnetic brake and/or a hydraulic brake, and may include anybraking actuation understood in the art. Additionally or alternatively,any brake may engage the lower countershaft 904, the upper countershaft902, or both. Where a different number of countershafts 902, 904 thantwo countershafts are present, any one or more of the countershafts maybe engagable by a brake.

The example countershaft 902 further includes a second engagementfeature 2804 configured to interface with a lubrication pump assembly1600, for example by a driving element 1712 that keys in to a slot ornotch on the countershaft 902. Any other engagement mechanism between atleast one of the countershafts 902, 904 is contemplated herein,including a friction contact and/or clutch, a belt or chain driving apump, and/or any other device known in the art.

The example countershaft 902 further includes a roller bearing 1108positioned at each respective end of the countershaft 902. ReferencingFIG. 31, a close-up detail of example roller bearings 1108 is depicted,with the first end roller bearing 1108 depicted in FIG. 31, and thesecond end roller bearing 1108 depicted in FIG. 32. The example rollerbearing details in FIGS. 31 and 32 depict NUP style cylindrical rollerbearings (e.g. having an integral collar in inner race, and a loosecollar mounted to the inner race), although any type of cylindricalroller bearing may also be utilized, and in certain embodiments adifferent type of bearing altogether (e.g. a journal bearing, needlebearing, or other type of bearing) may be utilized depending upon theexpected loads, required service life, and other aspects of a particularsystem. The example countershaft 902 further includes a countershaftsnap ring 2902 positioned and configured to retain each respectivebearing 1108, and one or more countershaft thrust washers 2806 (two, inthe example of FIG. 30) positioned on each side of the first end rollerbearing 1108. The number and placement of countershaft thrust washers2806 are non-limiting, with certain embodiments optionally excluding oneor more countershaft thrust washers 2806, and/or including countershaftthrust washers 2806 associated with the second end roller bearing 1108according to the loads observed and/or expected in a given transmission100.

Referencing FIG. 33, an example countershaft 902 is depicted. In theexample of FIG. 33, the countershaft 902 corresponds to an uppercountershaft in certain embodiments of the transmission 100, and issubstantially similar to the lower countershaft 904 in several aspects.The example countershaft 902 does not include engagement features 2802,2804 for a friction brake and/or a lubrication pump assembly 1600. Incertain embodiments, the upper countershaft 902 may engage one or moreof the friction brake and/or lubrication pump assembly 1600, eitherinstead of or in addition to the engagement of the lower countershaft904.

Referencing FIG. 34, an example planetary gear assembly 820 is depictedin cutaway view. The example planetary gear assembly 820 includes thesecond main shaft portion 806 coupled to a sun gear 3102, and thesliding clutch 920 that locks up the sun gear 3102, such that the secondmain shaft portion 806 directly drives the output shaft 926 (e.g. thesliding clutch 920 in forward position in the example of FIG. 34). Inthe locked up position, the planetary gears 3106 revolve around the sungear 3102, without any rotation in one example. The sliding clutch 920selectively couples the sun gear 3102 to planetary gears 3106 (e.g. in arearward position), which additionally rotate within a ring gear 2202 inaddition to revolving, providing gear reduction between the second mainshaft portion 806 and the output shaft 926. The example planetary gearassembly 820 includes a synchronization flange 3108 to transfer rotationfrom the planetary gears 3106 about the drive axis to the output shaft926. The example planetary gear assembly 820 includes a fixed plate 3112grounded to transmission 100 enclosures (e.g. a rear housing 108) to fixsun gear 3102 rotation to the planetary gear 3106 rotations, althoughalternate arrangements for a planetary gear assembly 820 arecontemplated herein. In certain embodiments, the third ball bearing 1106and a thrust washer 3110 take thrust loads, where present. The alignmentof ball bearings 1102, 1104, 1106, 1109 for example two on the secondmain shaft portion 806, and one on the input shaft 204, where the inputshaft 204 further includes a ball bearing upstream on a prime moverengagement shaft (not shown—e.g. an engine crankshaft), enforcesalignment of the driveline through the transmission, allowing the firstmain shaft portion 804 to float radially while avoiding fulcrum effectsand the bearings and consequential additional loads on the transmissiongears. The example planetary gear assembly 820 depicts a needle bearing3118 positioned between the second main shaft portion 806 and the outputshaft 926, and a thrust washer 3114 positioned on the second main shaftportion 806 side of the needle bearing 3118. The described type andposition of bearings, thrust management devices, and the like, as wellas the retaining mechanisms for those devices (e.g. the contours of theinner geometry of the second main shaft portion 806 and the output shaft926 in the example of FIG. 34) are non-limiting examples, and anyarrangement understood in the art is contemplated herein. The examplesecond main shaft portion 806 further includes a lubrication tube 3116,having holes therein to provide lubrication flow to bearings in fluidcommunication with the second main shaft portion 806, and a closetolerance rather than a seal between the lubrication tube 3116 (and/orlubrication sleeve) and the second main shaft portion 806. Theutilization of a close tolerance rather than a seal, in certainembodiments, utilizes resulting leakage as a controlled feature of thelubrication system, reducing losses from both constrained lubricationflow paths and friction from a seal.

Referencing FIG. 35, a detail view of the sliding clutch 920 andportions of the planetary gear assembly 820 are shown in cutaway view.The sliding clutch 920 engages a planetary synchronizer 3202 in arearward position, coupling the sun gear 3102 to the planetary gears3106, for example through the fixed plate 3112, which rotate within thering gear 2202 and provide gear reduction to the output shaft 926. Thesliding clutch 920 in the forward position locks up the sun gear 3102rotation to the output shaft 926, providing for direct drive. In theexample of FIG. 35, the second main shaft portion 806 is splined to thefirst main shaft portion 804, although alternative arrangements arecontemplated in the present disclosure.

Referencing FIG. 36, a detail view of an example output synchronizationassembly 3300 is depicted. The output synchronization assembly 3300includes the synchronization flange 3108 coupled to the planetary gearassembly 820 to bodily rotate with the planetary gear assembly 820. Asthe planetary gears 3106 rotate within the ring gear 2202, gearreduction through the planetary gear assembly 820 is provided. As theplanetary gears 3106 are fixed to the ring gear 2202, direct drivethrough the planetary gear assembly 820 is provided. A snap ring (notshown) may be provided to retain planetary gear bearings 3302, and aneedle roller bearing 3304 may be provided between each planetary gearbearing 3302 and the respective planetary gear 3106. In the exampleoutput synchronization assembly 3300, a thrust washer 3306 is providedat each axial end of the planetary gear bearings 3302.

Referencing FIG. 37, a portion of an output shaft assembly 110 isdepicted in a combined cutaway and exploded view. The example outputshaft assembly 110 includes the driveline adapter 928 and a couplingfastener 3402 (e.g. threaded appropriately to maintain position and/orhaving a retainer plate 3404). The example output shaft assembly 110further includes the fourth ball bearing 1109 coupled to the outputshaft 926, and an O-ring 3406 (e.g. for sealing) and/or a thrust washer3408 coupled to the fourth ball bearing 1109. The example output shaftassembly 110 further includes a hub seal 3410 and a slinger assembly3412, for example to provide lubrication to the output shaft assemblyand/or the fourth ball bearing 1109.

Referencing FIG. 38, an example of a portion of planetary gear assembly820 is depicted in proximity to a rear housing 108. The planetary gearassembly 820 depicts the planetary gears 3106 rotating on planetary gearbearings 3302 and positioned between a front disc 3502 and a toothedrear disc 3504. Referencing FIG. 39, a shift rail 3506 (e.g.operationally coupled to one of the additional actuation engagementpoints 1310, 1312 of the integrated actuator assembly 1300) isoperationally coupled to a fourth actuator 3508 (e.g. a shift fork) thatoperates the sliding clutch 920 to selectively lock up the planetaryassembly 820 (providing direct drive) and/or to allow the planetarygears 3106 to rotate within the ring gear 2202 and provide gearreduction across the planetary assembly 820. The example planetary gearassembly 820 depicts a roll pin 3510 coupling the fourth actuator 3508to the shift rail 3506, although any coupling mechanism understood inthe art is contemplated herein.

Referencing FIG. 40, an example transmission 100 is depicted havingfeatures consistent with certain embodiments of the present disclosure.The example transmission includes the integrated actuator housing 112positioned at the top of the transmission 100, with the TCM 114 mountedthereupon. The transmission 100 includes a number of lift points 412positioned thereupon. The transmission 100 includes a single powerinterface 3702 for actuation, for example for a pneumatic input (e.g. anair input port 302) from a vehicle air supply or other source, which incertain embodiments provides for a single connection to power allshifting and clutch actuators on the transmission 100. The exampletransmission 100 further includes the output shaft assembly 110,configured for certain driveline arrangements, including a drivelineadapter 928 coupled to an output shaft with a retainer plate 3404 andcoupling fastener 3402. The example transmission includes a sensor port304 configured to provide access for a sensor, for example an outputshaft speed sensor, and a sensor access 3704 allowing for a sensor to bepositioned within the transmission 100, for example within the rearhousing 108 in proximity to a rotating component in the rear housing 108such as the output shaft 926. The example transmission 100 furtherincludes the clutch housing 104, optionally integrated with theintegrated actuator housing 112, and also mounted on the top of thetransmission 100 in the example of FIG. 40. The transmission 100 furtherincludes a second sensor access 3706, for example providing a locationto mount an oil pressure sensor 406. In one example, the oil pressuresensor 406 couples to a lubrication pump assembly 1600, providing readyaccess to determine oil pressure for the transmission 100. The exampletransmission 100 further depicts an 8-bolt PTO interface 410 at thebottom of the transmission 100. In certain embodiments, the transmission100 does not include a cooling system (not shown), or a coolinginterface, to a vehicle or application in which the transmission 100 isinstalled. Alternatively, an example transmission 100 includes a coolingsystem (not shown), which may be a contained coolings system (e.g.transmission 100 includes a radiator or other heat rejection device, andis not integrated with a cooling system outside the body of thetransmission 100), and/or an integrated cooling system utilizing coolingfluid, heat rejection, or other cooling support aspects of a vehicle orapplication. In certain embodiments, one or more housing elements 102,104, 108 are made of aluminum, and/or one or more housing elements aremade of cast aluminum. The example transmission 100 includes a minimalnumber of external hoses and/or lines dedicated for transmissionoperation, for example zero external hoses and/or lines, a singleexternal line provided as a sensor coupler 404, a single external linecoupling an oil sensor coupler (not shown) that couples an oil pressuresensor 406 to the TCM 114, and/or combinations of these.

It can be seen that the example transmission 100 depicted in FIG. 40provides an easily manipulable and integratable transmission 100, whichcan readily be positioned in a driveline with a minimal number ofconnections—for example a single power interface, a wiring harnessconnection at the electrical connectors 402, and may require no coolantor other fluid interfaces. In certain embodiments, the transmission 100is similarly sized to previously known and available transmissions forsimilar applications, and in certain embodiments the transmission issmaller or larger than previously known and available transmissions forsimilar applications. In certain embodiments, the transmission 100includes housing elements 102, 104, 108 that provide additional spacebeyond that required to accommodate the internal aspects of thetransmission (gears, shafts, actuators, lubrication system, etc.), forexample to match the transmission 100 to an expected integration sizeand/or to utilize one or more housing elements 102, 104, 108 in multipleconfigurations of the transmission 100 (e.g. to include additional gearlayers on the input shaft 204 and/or first main shaft portion 804). Themodular construction of the housing elements 102, 104, 108, gears,shafts, lubrication pump assembly 1300, and other aspects of thetransmission 100 similarly promote re-usability of certain aspects ofthe transmission 100 across multiple configurations, while other aspects(e.g. clutch housing 104, main housing 102, and/or rear housing 108) arereadily tailored to specific needs of a given application orconfiguration. The example transmission 100 further provides for readyaccess to components, such as the actuators and/or clutch bearings,which in previously known and available transmissions require morecomplex access to install, service, integrate, and/or maintain thosecomponents. In certain embodiments the transmission 100 is a high outputtransmission; additionally or alternatively, the transmission 100 is ahigh efficiency transmission.

The term high output, as utilized herein, is to be understood broadly.Non-limiting examples of a high output transmission include atransmission capable of operating at more than 400, 500, 600, 700, 800,900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000,2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, and/or more than3000 foot-pounds of input torque at a specified location (e.g. at aclutch face, input shaft, or other location in the transmission).Additional or alternative non-limiting examples include a transmissioncapable of providing power throughput of more than 200, 250, 300, 350,400, 450, 500, 550, 600, 650, 700, 1000, 1500, 2000, 2500, 3000, and/ormore than 5000 horsepower, wherein power throughput includes the powerprocessed by the transmission averaged over a period of time, such as 1second, 10 seconds, 30 seconds, 1 minute, 1 hour, and/or 1 day ofoperation. Non-limiting examples of a high output transmission include atransmission installed in an application that is a vehicle having agross vehicle weight exceeding 8500, 14,000, 16,000, 19,500, 26,000,33,000, up to 80,000, up to 110,000, and/or exceeding 110,000 pounds.Non-limiting examples of a high output transmission include atransmission installed in an application that is a vehicle of at leastClass 3, at least Class 4, at least Class 5, at least Class 6, at leastClass 7, and/or at least Class 8. One of skill in the art, having thebenefit of the disclosures herein, will understand that certain featuresof example transmissions in the present disclosure may be beneficial incertain demanding applications, while the same or other features ofexample transmissions may be beneficial in other demanding applications.Accordingly, any described features may be included or excluded fromcertain embodiments and be contemplated within the present disclosure.Additionally, described examples of a high output transmission arenon-limiting, and in certain embodiments a transmission may be a highoutput transmission for the purposes of one application, vehicle, powerrating, and/or torque rating, but not for the purposes of otherapplications, vehicles, power ratings, and/or torque ratings.

The term “high efficiency,” as used herein, is to be understood broadly.A high efficiency transmission is a transmission having a relativelyhigh output value and/or high benefit level, in response to a giveninput value and/or cost level. In certain embodiments, the high outputvalue (and/or benefit level) is higher than that ordinarily present inpreviously known transmissions, the given input level (and/or costlevel) is lower than ordinarily present in previously knowntransmissions, and/or a difference or ratio between the high outputvalue (and/or benefit level) and the given input level (and/or costlevel) is greater than that ordinarily present in previously knowntransmissions. In certain embodiments, the output value and/or the inputlevel are within ranges observed in previously known transmissions, butthe transmission is nevertheless a high efficiency transmission—forexample because the difference or ratio between the high output valueand the given input level is high, and/or because other benefits ofcertain embodiments of the present disclosure are additionally evidentin the example transmission. A “high output value” should be understoodto encompass a relatively high level of the benefit—for example a lowerweight transmission has a higher output value where the weight isconsidered as the output side of efficiency. A “low input value” shouldbe understood to encompass a relatively low cost or input amount—forexample a lower weight transmission has a lower cost value where theweight is considered as the input side of the efficiency. Example andnon-limiting output values include a transmission torque level (input,output, or overall gear ratio), a number of available gear ratios, anoise reduction amount, a power loss description, a reliability,durability and/or robustness value, ease of maintenance, quality ofservice, ease of integration, and/or ease of installation, aresponsiveness value (e.g. clutch engagement and/or shifting), aconsistency value (e.g. repeatability of operations, consistent driverfeel, high degree of matching to a previously known configuration),transmission induced down time values, and/or a service life value.Example and non-limiting input values include a transmission cost,transmission weight, transmission noise level, engineering design time,manufacturing ease and/or cost, installation and/or integration time(e.g. time for the installation, and/or engineering work to prepare theinstallation plan and/or configure other parts of a vehicle orapplication to accommodate the transmission), a total cost of ownershipvalue, scheduled maintenance values, average maintenance and/or repairvalues (e.g. time and/or cost), transmission induced down time values,and/or application constraints (e.g. torque or power limits—absolute,time averaged, and/or in certain gear configurations). The describedexamples of a high efficiency transmission are non-limiting examples,and any high efficiency descriptions known to one of skill in the art,having the benefit of the disclosures herein, are contemplated withinthe present disclosure. One of skill in the art, having the benefit ofthe disclosures herein and information ordinarily known about acontemplated application or installation, such as the functions andpriorities related to performance, cost, manufacturing, integration, andtotal cost of ownership for the application or installation, can readilyconfigure a high efficiency transmission.

It can be further seen that the example transmission 100 provides, incertain embodiments, a reduction in overall bearing and gear loadsthroughout the transmission 100, for example through the utilization ofhigh speed countershafts, helical gearing to improve and/or optimizesliding speeds and gear loading, and/or gear tooth shaping to configuregear tooth contact area, structural integrity, and control of slidingspeed profiles and deflection of gear teeth. In certain embodiments, theuse of high speed countershafts allows smaller and/or lightercomponents, including at least rotating components (e.g. shafts andgears), bearings, and lubrication systems. In certain embodiments, theutilization of helical gears and/or shaped gear teeth allows forreduction in sliding losses (e.g. increased power transfer efficiencyand reduction in heat generated) while also allowing a transmission 100to meet noise constraints. In certain embodiments, the configuration toallow for noise control allows for certain aspects of the transmission100 to be configured for other desirable purposes that otherwise wouldincrease the noise emissions from the transmission 100, such as the useof aluminum housings, configuring for ease of access to shift and/orclutch actuators, the use of a linear clutch actuator, and/orpositioning of access to major transmission features, such as actuators,at the top of the transmission which may put them in proximity to apassenger compartment or other noise sensitive area in an application orvehicle. In certain embodiments, the use of helical gearing allows adegree of freedom on thrust (axial) loads, directing thrust loads toselected positions in the transmission 100 such as a support bearingand/or a bearing positioned between shafts having low speeddifferentials, and/or away from housing enclosures or bearings.

In certain embodiments, the utilization of high speed countershaftsadditionally or alternatively reduces speed differences between shafts,at least at selected operating conditions, and supports the managementof thrust loads in the transmission 100. In certain embodiments, helicalgears on a planetary gear assembly provides for a reduced length ofcountershafts (e.g. countershafts do not need to extend to the outputshaft), a reduction in a number of countershafts (e.g. additionalcountershafts for power transfer between a main shaft and the outputshaft are not required). Additionally or alternatively, helical gears ona planetary gear assembly are load balanced, in certain embodiments, toremove gear loading from enclosures and/or bearings coupled toenclosures. In certain embodiments, features of the transmission 100,including but not limited to thrust load management features, providefor load management with the use of efficient bearings, for example,with a reduced number of or elimination of tapered bearings in thetransmission 100. In certain embodiments, features of the transmission100 include a high efficiency lubrication system, for exampleutilization of a smaller lubrication pump (e.g. short lubrication runswithin the transmission 100, reduction or elimination of spinning shaftslip rings in the transmission 100, and/or higher pump speed powered bya high speed countershaft), the use of a dry sump lubrication system,and/or the use of a centrally located lubrication pump assembly. Incertain embodiments, the transmission 100 provides for lower powertransfer losses than previously known transmissions, and/or provides forsimilar or improved power losses in an overdrive transmission relativeto previously known transmission systems using direct drive, allowingfor other aspects of a system or application to operate at lower speedsupstream of the transmission (e.g. prime mover speed) and/or higherspeeds downstream of the transmission (e.g. a load component such as adriveline, rear axle, wheels, and/or pump shaft) as desired to meetoperational goals of those aspects.

In certain embodiments, the transmission 100 utilizes a clutch andshifts gears utilizing actuators that move gear shifting elements oractuators (e.g utilizing shift forks and sliding clutches, withsynchronizer elements). An example and non-limiting application forembodiments of the transmission is an automated transmission, and/or amanual automated transmission. Certain aspects and features of thepresent disclosure are applicable to automatic transmissions, manualtransmissions, or other transmission configurations. Certain features,groups of features, and sub-groups of features, may have applicabilityto any transmission type, and/or may have specific value to certaintransmission types, as will be understood to one of skill in the arthaving the benefit of the present disclosure.

Referencing FIG. 41, an example clutch operation assembly 3800 isdepicted illustrating certain aspects of a clutch assembly andoperational portions of the transmission 100 interacting with the clutchassembly. The example clutch operation assembly 3800 provides a clutch106 that is responsive to a linear clutch actuator 1002, and thatadjusts a position of the clutch 106 such that, as the clutch face wears306, the engagement point of the linear clutch actuator 1002 remainsconstant for a selectable amount of wear on the clutch face 306. Theinclusion of a clutch operation assembly 3800 responsive to a linearclutch actuator 1002, and/or that provides for a constant engagementpoint for a linear or concentric clutch actuator, are optionalconfigurations that are included in certain embodiments of thetransmission 100, and may not be included in other embodiments of thetransmission 100. Any clutch operation assembly 3800 known in the art iscontemplated herein, including alternate arrangements to provide forengagement with a linear clutch actuator 1002, and/or alternatearrangements to provide for maintenance of an engagement point for aclutch actuator over a selectable amount of wear on the clutch face 306.In certain embodiments, the liner actuator 1002 is additionally oralternatively self-adjusting, allowing for the actuating volume for theactuator to remain consistent as the clutch, clutch engagement yoke 808,linear actuator 1002, and/or other aspects of the system wear and/orchange over the life cycle of the transmission 100. In certainembodiments, the actuating volume is consistently maintained as anear-zero actuating volume. In certain embodiments, the consistency ofthe actuating volume and/or a maintained near-zero actuating volumeprovides for improved response time and improved control accuracythroughout the life cycle of the transmission 100, and provides forqualitative improvements in clutch operation such as capabilities toutilize the clutch rapidly during shifts (e.g., to mitigate tooth buttevents and/or reduce backlash impact on gear meshes).

The example clutch operation assembly 3800 includes the input shaft 204and the release bearing 1118, and the clutch face 306 that engages theprime mover. The example clutch operation assembly 3800 further includesa diaphragm spring 3802 that biases the clutch face 306 to an engagedposition (toward the prime mover and away from the transmission 100),and upon actuation by the clutch engagement yoke 808 (e.g. the clutchengagement yoke 808 pushed forward by the clutch actuator 1002)withdraws the clutch face 306 from the engaged position. Any otheractuation mechanism for a clutch is contemplated herein. The clutchoperation assembly 3800 further includes a bearing housing 3804 thatengages and retains the release bearing 1118, and further includes alanding face on the release bearing 1118 that engages the clutchengagement yoke 808.

Referencing FIG. 42, a portion of the clutch operation assembly 3800 isdepicted in exploded view. The clutch operation assembly 3800 includesthe clutch 106, having torsion springs 4202 and a pre-damper assembly4006 coupled thereto. The clutch operation assembly 3800 includes apressure plate assembly 4004 and the diaphragm spring assembly bracket4002. Referencing FIG. 43, a detail view of the example pressure plateassembly 4004 is depicted in a perspective view (FIG. 43) and a sidecutaway view (FIG. 44). The example pressure plate assembly 4004includes a cam ring 4504 and control fingers 4506 coupled to a pressureplate 4508. The cam ring 4504 rotates and cooperates with the controlfingers 4506 to position the clutch 106 such that, as the clutch facewears 306, the release bearing 1118 maintains a same position relativeto the clutch engagement yoke 808. Accordingly, even as the clutch face306 wears, the clutch actuator 1002 returns to the same position withinthe clutch actuator housing 104. After a selected amount of wear, thecontrol fingers 4506 prevent further adjustment, and the clutch actuator1002 will no longer return all the way to the starting point.Accordingly, a high degree of responsiveness and repeatability forclutch engagement is provided in the example transmission 100, whileallowing for diagnostics and/or detection of clutch face 306 wear, wherethe clutch is still operable but the clutch actuator 1002 returnposition responds to clutch face 306 wear. The example pressure plateassembly 4004 includes a torsion spring (not shown) coupled to the camring 4504 to urge rotation of the cam ring 4504 as the clutch face 306wears, and a cam baffle 4510 having teeth thereon to preventcounter-rotation of the cam ring 4504.

Various example embodiments of the present disclosure are describedfollowing. Any examples are non-limiting, and may be divided orcombined, in whole or part. The example embodiments may include anyaspects of embodiments throughout the present disclosure.

Certain embodiments of a high efficiency transmission are describedfollowing. The description of certain characteristics as promotingtransmission efficiency are provided as illustrative examples.Efficiency promoting characteristics may be included in a particularembodiment, while other characteristics may not be present. Efficiencypromoting characteristics may be combined, used in part whereapplicable, and sub-groupings of any one or more of the describedefficiency characteristics may be included in certain embodiments. Thedescription of any feature or characteristic as an efficiency-promotingfeature is not limiting to any other feature of the present disclosurealso promoting efficiency, and in certain embodiments it will beunderstood that a feature may promote efficiency in certain contextsand/or applications, and decrease efficiency in other contexts and/orapplications.

An example transmission 100 includes one or more housing elements 102,104, 108 that are made at least partially of aluminum. In certainembodiments, housing elements 102, 104, 108 may be cast aluminum. Theuse of aluminum introduces numerous challenges to the performance of atransmission 100, and in certain embodiments introduces more challengeswhere the transmission 100 is a high output transmission. For example,and without limitation, aluminum is typically not as strong as steel fora given volume of material, is softer than steel, and has differentstress characteristics making it less robust to stress in certainapplications. Changes to the stress capability of the housing materialhave consequences throughout the transmission—for example bolt bossesgenerally must be deeper for equivalent robustness, and housingenclosures have to be thicker and/or have stress management features forequivalent stresses experienced at the housing. Aluminum also does notinsulate noise as well as offset materials, such as steel.

The example transmission 100 includes a power thrust managementarrangement that neutralizes, cancels, reduces, and/or redirects theprimary power thrust loads experienced within the transmission. Incertain embodiments, the power thrust management arrangement redirectsthrust loads away from housings and/or transmission enclosures, allowingfor reduced strength of the housings with sufficient durability androbustness for a high output transmission. An example power thrustmanagement arrangement includes helical gears in the power transfer linethroughout the transmission 100—for example the countershaft 902, 904gear meshes—where the helical gear angles are selected to neutralize,reduce, and/or redirect primary power thrust loads experienced withinthe transmission 100. The adjustments of thrust loads may be, in certainembodiments, improved or optimized for certain operating conditions—forexample gear ratios likely to be engaged a higher load conditions, gearratios likely to be involved in higher speed differential operationsacross thrust bearings, and the like. A gear engagement on the inputshaft 204 side of the transmission 100 with the countershaft 902, 904has one or more corresponding gear engagements on the first main shaftportion 804 side of the transmission 100 (depending upon the availablegear ratios and gear shifting plan), and the thrust management aspectsof the helical gears include selected helix angles for the various gearmeshes to adjust the thrust profile and thrust duty cycle of thetransmission 100. Certain considerations in determining the helical geargeometries include, without limitation: the load duty cycle for theapplication, installation, or vehicle (loads and/or speeds, as well asoperating time), the gear ratios at each mesh and the duty cycle ofopposing gear mesh engagement scenarios, and noise and efficiencycharacteristics of the helical gear ratio selections. One of skill inthe art, having the benefit of the present disclosure and informationordinarily available about a contemplated system, can readily determinehelical gear ratios to perform desired power thrust managementoperations in a transmission 100. In certain embodiments, thrust loadsare redirected to a thrust management device, such as a thrust bearing,which is positioned between rotating shafts having a lowest speeddifferential (e.g. the input shaft 204 to first main shaft portion 804).In certain embodiments, the transmission 100 does not include taperedbearings.

An example transmission 100 includes a low loss lubrication system.Losses, in the present instance, refer to overall power consumption fromthe lubrication system, regardless of the source of the powerconsumption, and including at least pumping work performed by thelubrication system, viscous losses of moving parts in the transmission100, and/or parasitic losses in the lubrication system. The example lowloss lubrication system includes a dry sump, wherein the rotatingportions of the transmission 100 (e.g. gears, shafts, and countershafts)are not positioned, completely and/or partially, within lubricatingfluid in the sump. An example lubrication pump assembly 1600, drawinglubrication fluid for the pump from the rear housing 108, provides anon-limiting example of a lubrication system having a dry sump. Anexample low loss lubrication system further includes a centralizedlubrication pump, such that lubrication paths within the transmission100 have a shortened length, and/or a reduced or optimized overalllength of the lubrication channels. An example lubrication pump assembly1600, integrated within the transmission 100 and coupled to acountershaft or other rotating element of the transmission 100, providesa non-limiting example of a centralized lubrication system. In certainembodiments, utilization of centralized lubrication tubes 1802 and/or1804 provide for reduced-length runs of lubrication channelsAdditionally or alternatively, an example transmission 100 includes alubrication tube positioned inside the first main shaft portion and/orsecond main shaft portion, having holes therein to provide a portion ofthe lubrication paths to one or more bearings, and additionally oralternatively does not include seals on the lubrication tube. In certainfurther embodiments, a low loss lubrication system includes alubrication pump driven by a high speed countershaft, where the highspeed of the countershaft provides for a higher lubrication pump speed,thereby allowing for a smaller lubrication pump to perform lubricationpumping operations, reducing both pumping losses and/or weight of thelubrication pump and/or associated lubrication pump assembly 1600.

An example transmission 100 includes one or more high speedcountershafts 902, 904. The term “high speed” with reference tocountershafts, as utilized herein, is to be understood broadly. Incertain embodiments, a high speed countershaft rotates at a similarspeed to the input shaft 204 and/or the first main shaft portion 804,for example at the same speed, within +/−5%, +/−10%, +/−15%, +/−20%,+/−25%, and/or within +/−50% of the speed of the input shaft 204 and/orfirst main shaft portion 804. In certain embodiments, a high speedcountershaft has a higher relative speed than a countershaft in anoffset transmission for a similar application, where similarity ofapplication may be determined from such considerations as power rating,torque rating, torque multiplication capability, and/or final loadoutput and/or duty cycle. A speed that is a high relative speed to anoffset transmission includes, without limitation, a speed that is atleast 10% higher, 20% higher, 25% higher, 50% higher, 100% higher, up to200% higher, and greater than 200% higher. In certain embodiments,utilization of high speed countershafts 902, 904, allows for smallerdevices operating in response to the rotational speed of thecountershafts—for example a lubrication pump driven by a countershaft902, 904. In certain embodiments, a PTO device driven by one of thecountershafts can utilize the higher countershaft speed for improvedperformance. In certain embodiments, utilization of high speedcountershafts 902, 904 allows for reductions of gear and bearingcomponents, as the countershaft operates at a speed closer to the inputshaft and/or first main shaft portion speed than in a previously knowntransmission, providing for lower loads on meshing gears and bearings,and/or providing for more rapid gear shifts with lower losses (less timeto shift, and/or less braking to bring the countershaft speed closer tothe engaging speed, for example on an upshift). In certain embodiments,lower loads on the countershafts, due to the high speed configurationand/or a twin configuration sharing loads, allows for the countershaftto be a lower size and/or weight. In certain embodiments, the twincountershafts provide for noise reduction, for example from reduced sizeof engaging components and/or lower engagement forces. Additionally oralternatively, lower rotational inertia from the countershafts has alower effect on clutch speed during shifts—for example through transferof countershaft inertia to the clutch before clutch re-engagement,allowing for a faster and lower loss (e.g. lower braking applied to slowthe system back down) shifting event.

In certain embodiments, a gear ratio at the front of the transmission100 is lower relative to a gear ratio at the rear of the transmission100. In certain embodiments, providing greater torque amplification atthe rear of the transmission (e.g. from the countershaft(s) to thesecond main input shaft portion 804) than at the front of thetransmission 100 (e.g. from the input shaft 204 to the countershaft(s))provides for more efficient (e.g. lower losses) power transfer than moreevenly stepping up torque amplification. For example, a total ratio of4:1 provided as a first step of 1:1 and a second step of 4:1 for mostexample transmissions 100 provides for a lower loss power transfer thana first step of 2:1 and a second step of 2:1, while providing the sameoverall torque amplification. In certain embodiments, a rear:frontamplification ratio is greater than 1.5:1, greater than 2:1, greaterthan 2.5:1, greater than 3:1, greater than 3.5:1, greater than 4:1,greater than 4.5:1, and/or greater than 5:1. For example, where anoverall torque amplification ratio of 5:1 is desired, an exampletransmission includes a front transfer of 1.25:1 and a rear transfer of4:1. The described ratios and embodiments are non-limiting examples. Oneof skill in the art, having the benefit of the disclosures herein, willreadily appreciate that, in certain embodiments, high speedcountershafts facilitate lower front torque amplification ratios—forexample at a torque amplification ratio near unity (1), gear teeth countbetween the countershaft and the input shaft are also near unity, andaccordingly gear sizes can be kept low if the countershaft turns at ahigh rate of speed. In certain embodiments, a high speed countershaftfacilitates selection of gear sizes to meet other constraints such asproviding an interface to a PTO device, providing for gear geometrieswithin a transmission 100 to facilitate manufacture and assembly withina cast housing, and/or to keep gear outer diameters in a normal range.Gear sizes provided within a normal range—i.e. not constrained to belarge on either the input shaft 204 and/or the countershaft 902, 904 bytorque amplification requirements—allow for controlling torsional forceson the shafts and gear fixing mechanisms (e.g. welds and/or synchronizerdevices) low and/or controlling a final geometric footprint of thehousing (e.g. the main housing 102) to provide for a compact and/oreasily integrated transmission 100.

In certain embodiments, a twin countershaft arrangement provides forbalanced forces on the input shaft 204 and/or first main shaft portion804, and lower cost bearings at one or more gear locations on the inputshaft 204 and/or first main shaft portion 804 are provided—for example ajournal bearing, bushing, a washer, and/or a race bearing. In certainembodiments, a needle bearing is provided at one or more gear locationson the input shaft 204 and/or the main shaft portion 804, for example ona gear expected to take a radial load, including, for example, a gear onthe input shaft 204 close to the power intake for the transmission 100,and/or a gear coupled to the countershaft for powering a PTO device.

In certain embodiments, helical gearing on the countershafts 902, 904and meshing gears thereto provides for high efficiency operation for thetransmission 100. For example, helical gearing provides for thrustmanagement control of the power transfer in the transmission, allowingfor lower weight and cost components, such as bearings. Additionally oralternatively, thrust management control of the gears allows for reducedhousing weight and/or strength for a given power or torque throughput.Additionally or alternatively, helical gear engagement allows forreduced noise generation, allowing for greater engagement force betweengears for a given noise level. Additionally or alternatively, helicalgears are easier to press and time relative to, for example, spurgears—allowing for a reduced manufacturing cost, improvedmanufacturability, and/or more reliable gear mesh. Additionally oralternatively, helical gears provide a greater contact surface for gearteeth, allowing for lower contact pressure for a given contact force,and/or lower face width for the gear teeth while providing gear teeththat are readily able to bear contact loads.

In certain embodiments, a transmission 100 is provided without taperedbearings in the drive line. In certain embodiments, a transmission 100has a reduced number of tapered bearings in the drive line relative toan offset transmission in a similar application. Tapered bearings aretypically utilized to control both thrust loads and radial loads. Incertain embodiments, a transmission 100 includes features to controlthrust loads, such that tapered bearings are not present. Taper rollerson a bearing require shimming and bearing clearance settings. In certainembodiments, tapered bearings reduce power transfer efficiency andgenerate additional heat in the transmission. In certain embodiments,main bearings in an example transmission 100 are positioned (e.g.pressed) in the housing elements 102, 104, 108, and shafts in thedriveline are passed therethrough. An example transmission 100 isassembled positioned vertically, with shafts passed through the pressedbearings, and where no bearing clearances and/or shims need to be made,the main housing 102 is coupled to the clutch housing 104 duringvertical assembly, and the rear housing 108 is coupled to the mainhousing 102 to complete the housing portion of the vertical assembly. Incertain embodiments, an example transmission 100 may be constructedhorizontally or in another arrangement, and/or vertically with the rearhousing 108 down.

In certain embodiments, power transfer gears in the transmission 100(e.g. at the countershaft meshes) gear teeth have a reduced heightand/or have a flattened geometry at the top (e.g. reference FIG.24—teeth have a flattened top profile). The use of shortened teethprovides for lower sliding velocities on gear teeth (e.g. increasedpower transfer efficiency) while allowing the teeth to engage in a highpower transfer efficiency operation. The shortened gear teeth, wherepresent, additionally experience lower deflection than occurs at the topof previously used gear teeth geometries, providing greater control ofone noise source and improved service life of the gear teeth. In certainembodiments, the use of helical gears with a flattened tooth geometryallows for further noise control of flattened gear teeth and/or highpower transfer loads. In certain embodiments, a low tolerance and/orhigh quality manufacturing operation for the gear teeth, such as the useof a wormwheel to machine gear teeth, provides for a realized geometryof the gear teeth matching a design sufficiently to meet noise and powertransfer efficiency targets. In certain embodiments, a worm wheel isutilized having a roughing and finishing grit applied in one pass,allowing gear tooth construction to be completed in a single pass of thewormwheel and leave a selected finish on the gear tooth.

In certain embodiments, the transmission 100 includes thrust loadscancelled across a ball bearing, to control thrust loads such that nobearings pressed into a housing enclosure take a thrust load, to controlthrust loads such that one or more housing elements do not experiencethrust loads, to control thrust loads such that a bearing positionedbetween low speed differential shafts of the transmission (e.g. betweenan input shaft 204 and a first main shaft portion 804) take the thrustloads, and/or such that thrust loads are cancelled and/or reduced byhelical gears in power transfer gear meshes. In certain embodiments,bearings pressed into a housing element, and/or one or more housingelements directly, are exposed only to radial loads from power transferin the transmission 100.

In certain embodiments, a transmission 100 includes a PTO interface 410configured to allow engagement of a PTO device to one of thecountershafts from a radial position, for example at a bottom of thetransmission 100. An example transmission 100 includes gearconfigurations such that a radially extending gear from one of thecountershafts 902, 904 is positioned for access to the extending gearsuch that a gear to power a PTO device can be engaged to the extendinggear. Additionally or alternatively, a corresponding gear on one of theinput shaft 204 and/or first main shaft portion 804 includes a needlebearing that accepts radial loads from the PTO engagement. In certainembodiments, the countershafts 902, 904 do not include a PTO engagementgear (e.g. at the rear of the countershaft), and the transmission 100 isconfigured such that driveline intent gears can be utilized directly forPTO engagement. Accordingly, the size and weight of the countershafts isreduced relative to embodiments having a dedicated PTO gear provided onone or more countershafts. In certain embodiments, a second PTO access(not shown) is provided in the rear housing, such that a PTO device canalternatively or additionally engage at the rear of the transmission.Accordingly, in certain embodiments, a transmission 100 is configurablefor multiple PTO engagement options (e.g. selectable at time ofconstruction or ordering of a transmission), including a 8-bolt PTOaccess, and/or is constructed to allow multiple PTO engagement optionsafter construction (e.g. both PTO access options provided, such as witha plug on the rear over the rear PTO access, and an installer/integratorcan utilize either or both PTO access options).

An example transmission 100 includes only a single actuator connectionto power actuators in the transmission, for example an air input port302 provided on the integrated actuator housing 112. A reduction in thenumber of connections reduces integration and design effort, reducesleak paths in the installation, and reduces the number of parts to beintegrated into, and/or fail in the installed system. In certainembodiments, no external plumbing (e.g. lubrication, coolant, and/orother fluid lines) is present on the transmission 100. In certainembodiments, the transmission 100 is a coolerless design, providing lesssystems to fail, making the transmission 100 more robust to a coolingsystem failure of the application or vehicle, reducing installationconnections and integration design requirements, reducing leak pathsand/or failure modes in the transmission and installed application orvehicle, and reducing the size and weight footprint of the transmission100. It will be recognized that certain aspects of example transmissions100 throughout the present disclosure support a coolerless transmissiondesign, including at least transmission power transfer efficiencyimprovements (e.g. generating less heat within the transmission to bedissipated) and/or aluminum components (e.g. aluminum and commonaluminum alloys are better thermal conductors than most steelcomponents). In certain embodiments, heat fins can be included onhousing elements 102, 104, 108 in addition to those depicted in theillustrative embodiments of the present disclosure, where additionalheat rejection is desirable for a particular application. In certainembodiments, an example transmission 100 includes a cooler (not shown).

In certain embodiments, a transmission 100 includes an organic clutchface 306. An organic clutch face provides for consistent and repeatabletorque engagement, but can be susceptible to damage from overheating. Itwill be recognized that certain aspects of example transmissions 100throughout the present disclosure support utilization of an organicclutch face 306. For example, the linear clutch actuator 1002, andclutch adjustment for clutch face wear providing highly controllable andrepeatable clutch engagement, allow for close control of the clutchengagement and maintenance of clutch life. Additionally oralternatively, components of the transmission 100 providing for fast andsmooth shift engagements reduce the likelihood of clutch utilization toclean up shift events—for example the utilization of high speedcountershafts, lower rotational inertia countershafts, helical gears,efficient bearings (e.g., management of shaft speed transients relativeto tapered bearing embodiments), and/or compact, short-run actuationsfor gear switching with an integrated actuator assembly. In certainembodiments, elements of the transmission 100 for fast and smooth shiftengagements improve repeatability of shift events, resulting in a moreconsistent driver feel for a vehicle having an example transmission 100,and additionally or alternatively the use of an organic clutch face 306enhances the ability to achieve repeatable shift events that provide aconsistent driver feel.

In certain embodiments, a transmission 100 is configurable for a numberof gear ratios, such as an 18-speed configuration. An example 18-speedconfiguration adds another gear engaging the input shaft 204 with acorresponding gear on the countershaft(s). The compact length of theexample transmissions 100 described herein, combined with the modularconfiguration of housing elements 102, 104, 108 allow for the readyaddition of gears to any of the shafts, and accommodation of additionalgears within a single housing configuration, and/or isolated changes toone or more housing elements, while other housing elements accommodatemultiple gear configurations. An example 18-speed configuration is a3×3×2 configuration (e.g. 3 gear ratios available at the input shaft204, 3 forward gear ratios on the first main shaft portion 804, and 2gear ratios available at the second main shaft portion 806).Additionally or alternatively, other arrangements to achieve 18 gears,or other gear configurations having more or less than 12 or 18 gears arecontemplated herein.

In certain embodiments, certain features of an example transmission 100enable servicing certain aspects of the transmission 100 in a mannerthat reduces cost and service time relative to previously knowntransmissions, as well as enabling servicing of certain aspects of thetransmission 100 without performing certain operations that requireexpensive equipment and/or introduce additional risk (e.g. “dropping thetransmission,” and/or disassembling main portions of the transmission100).

An example service event 5600 (reference FIG. 45) includes an operation5602 to access an integrated actuator assembly, by directly accessingthe integrated actuator assembly from an external location to thetransmission. In certain embodiments, the integrated actuator assemblyis positioned at the top of the main housing 102, and is accessed insingle unit having all shift and clutch actuators positioned therein. Incertain embodiments, one or more actuators may be positioned outside ofthe integrated actuator assembly, and a number of actuators may bepositioned within or coupled to the integrated actuator assembly. Directaccess to an integrated actuator assembly provides, in certainembodiments, the ability to install, service, and/or maintain actuatorswithout dropping the transmission, disassembling main elements of thetransmission (including at least de-coupling one or more housings, theclutch, any bearings, any gears, and/or one or more shafts).Additionally or alternatively, the example service event 5600 includesan operation 5604 to decouple only a single actuator power input,although in certain embodiments more than one actuator power input maybe present and accessed. The example service event 5600 includes anoperation 5606 to service the integrated actuator assembly, such as butnot limited to fixing, replacing, adjusting, and/or removing theintegrated actuator assembly. The term “service event,” as utilizedherein, should be understood to include at least servicing, maintaining,integrating, installing, diagnosing, and/or accessing a part to provideaccess to other parts in the transmission 100 or system (e.g. vehicle orapplication) in which the transmission is installed.

An example service event 5900 (reference FIG. 46) includes an operation5902 to access a journal bearing 2602 positioned at an engagement end ofthe input shaft 204. The engagement end of the input shaft 204 engagesthe prime mover, for example at a ball bearing in the prime mover (notshown), and the engagement end of the input shaft 204 can experiencewear. The inclusion of a journal bearing 2602, in certain embodiments,provides for ready access to replace this wear part without removaland/or replacement of the input shaft 204. The example service event5900 further includes an operation 5904 to remove the journal bearing2602, and an operation 5906 to replace the journal bearing 2602 (forexample, after fixing the journal bearing 2602 and/or replacing it witha different part). The example service event 5900 describes a journalbearing 2602 positioned on the input shaft 204, however the journalbearing 2602 may be any type of wear protection device, including anytype of bearing, bushing, and/or sleeve.

Referencing FIG. 47, a perspective view of an example clutch housing 104consistent with certain embodiments of the present disclosure isdepicted. The clutch housing 104 includes an interface portion 4702 thatallows for coupling to a prime mover. The modularity of the clutchhousing 104 allows for ready configuration and integration for specificchanges, for example providing an extended or split input shaft to add agear layer to the input shaft without significantly altering thefootprint of the transmission 100, or requiring redesign of otheraspects of the transmission 100, while maintaining consistent interfacesto the prime mover.

Referencing FIG. 48, another perspective view of an example clutchhousing 104 consistent with certain embodiments of the presentdisclosure is depicted. The clutch housing 104 includes a secondinterface portion 4808 that allows for coupling to a main housing 102.The modularity of the clutch housing 104 allows for ready configurationand integration for specific changes, for example providing an extendedor split input shaft to add a gear layer to the input shaft withoutsignificantly altering the footprint of the transmission 100, orrequiring redesign of other aspects of the transmission 100, whilemaintaining consistent interfaces to the main housing 102. The exampleclutch housing 104 further includes holes 4802 for countershafts in abulkhead (or enclosure) formed on the main housing 102 side of theclutch housing 104, and a hole 4804 for passage of the input shafttherethrough. The integral bulkhead holes 4802, 4804 provide formounting of bearings and shafts, and for ready assembly of thetransmission 100.

Referencing FIG. 49, a perspective view of an example rear housing 108consistent with certain embodiments of the present disclosure isdepicted. The rear housing 108 includes an interface portion 4902 thatallows for coupling to a main housing 102. The modularity of the rearhousing 108 allows for ready configuration and integration for specificchanges, for example providing a rear PTO interface 5102 (see thedisclosure referencing FIG. 51) or other alterations to the rear housing108, without significantly altering the footprint of the transmission100, or requiring redesign of other aspects of the transmission 100.Referencing FIG. 50, another perspective view of the rear housing 108 isdepicted. The rear housing 108 includes a driveline interface 5002, forexample to couple with a driveshaft or other downstream component.Referencing FIG. 51, a perspective view of another example rear housing108 is depicted, providing a rear PTO interface 5102.

Referencing FIG. 52, a perspective view of an example lubrication pumpassembly 1600 consistent with certain embodiments of the presentdisclosure is depicted. The driving element 1712, coupling thelubrication pump 1704 to one of the countershafts, is visible in theperspective view of FIG. 52. The modularity of the lubrication pumpassembly 1600 allows for ready configuration and integration forspecific changes, for example providing an alternate pump sizing or gearratio, while maintaining consistent interfaces to the rest of thetransmission 100. Referencing FIG. 53, another perspective view of anexample lubrication pump assembly 1600 is depicted. An oil pickup screen1718 and screen retainer 1720 is visible in the view of FIG. 53.

Referencing FIG. 54, a perspective view of an example main housing 102consistent with certain embodiments of the present disclosure isdepicted. The example of FIG. 54 has a connector for a transmissioncontrol module, but the transmission control module is not installed.The main housing 102 includes interfaces 5402, 5404 (see the portion ofthe disclosure referencing FIG. 56) providing consistent interfaces tothe rear housing 108 and clutch housing 104. A clutch actuator housing202, which may be coupled to or integral with an integrated actuatorhousing 112 is visible in the view of FIG. 54. Referencing FIG. 55, atransmission control module 114 (TCM), and a TCM retainer 5502 (e.g., aTCM cover 1402) are depicted as installed on a transmission 100.Referencing FIG. 56, an 8-bolt PTO interface 410 is depicted, which maybe optionally not present or capped, without affecting the footprint orinterfaces of the main housing 102. Referencing FIG. 57, a bottom viewof an example main housing 102 is depicted, providing a clear view of anexample 8-bolt PTO interface 410. Referencing FIG. 58, a perspectiveview of an example main housing 102 is depicted, including an actuatorinterface 5802 whereupon actuators for shifting, clutch control, and/ora friction brake can be installed. Accordingly, the main housing 102 canaccommodate various actuation assemblies, including an integratedactuation assembly, without changing the footprint or interfaces of themain housing 102 with the rest of the transmission 100.

Embodiments depicted in FIGS. 59-94, and all related descriptionsthereto, are compatible in certain aspects to embodiments depicted inFIGS. 1-58, 95-100, and all related descriptions thereto. Accordingly,each aspect described in FIGS. 1-58 and 95-100 is contemplated asincluded, at least in one example, with any compatible embodimentsdescribed in FIGS. 59-94. For purposes of illustration of certaindisclosed features or principles, certain more specific relationshipsare described between embodiments depicted in FIGS. 1-58 and 95-100 andembodiments depicted in FIGS. 59-94, and additionally between disclosedembodiments within FIGS. 1-58 and 95-100 individually, and disclosedembodiments within FIGS. 95-100 individually. Such additionalspecifically described relationships are not limiting to otherrelationships not specifically described. One of skill in the art willrecognize compatible embodiments between all of the disclosed examplesherein, and any such compatible embodiments, in addition to any specificrelationships described, are contemplated herein.

Referencing FIG. 59, an example system 17100 is disclosed having atransmission 100, a prime mover 17102, a driveline 17108, and acontroller 17110 for a transmission 100. The example system 17100depicted schematically to illustrate relationships of certain elementsof the system 17100, and the described relationships between elementsand the selection of elements included are non-limiting examples.Additionally, the system 17100 may include additional elements notdepicted, including, without limitation, any elements present in FIGS.1-100 or otherwise described throughout the present disclosure. Incertain embodiments, the transmission 100 may be a transmissioncompatible with one or more embodiments depicted in FIGS. 1-100 and/ordescribed in the referencing sections thereto. Additionally oralternatively, the transmission 100 may be any type of torque transferdevice understood in the art.

The example system 17100 includes the prime mover 17102, which may beany type of power initiation device as understood in the art. Examplesinclude, without limitation, an internal combustion engine, a dieselengine, a gasoline engine, a natural gas engine, a turbine engine, ahydraulic pump, or other power source. In certain embodiments, the primemover 17102 is an internal combustion engine associated with a vehicle(not shown), an internal combustion engine associated with an on-highwayvehicle, an internal combustion engine associated with a heavy-dutyapplication, and/or an internal combustion engine associated with anon-highway heavy-duty truck, such as a Class 8 truck or similarapplication classified under a different system than the United States(US) truck classification system. In certain embodiments, the primemover 17102 provides requested torque for the application, which ismultiplied according to selected parameters through the transmission100, which may include reversing a direction of the torque (e.g. toreverse the movement direction of a vehicle). On-highway vehicleapplications are subjected to a number of challenges and constraints forthe system 17100, including at least: significant pressure onacquisition cost for the system (e.g. the capital cost of acquiring theparts of the system); significant pressure on operating cost of thesystem (e.g. costs for fuel consumption, repairs, maintenance, and/ordown time); highly transient operation of the system (e.g. to enabledesired acceleration or deceleration, to respond to rapidly changingon-highway conditions, to navigate road grades, and/or manage altitudeconditions); and significant pressure to maintain system repeatabilityand consistency (e.g. to protect the subject driver experience so theycan focus on driving safely instead of changes in the system response,to reduce driver fatigue from managing changing or unexpected systemresponse, to improve driver comfort in operation such as smooth anddesired response, to reduce noise emitted by the system, and/or to meetperformance expectations of a driver, owner, or fleet operator).On-highway vehicle applications in the heavy duty truck space, and/or inthe Class 8 truck space, include these challenges, and in some instancesmake these challenges even more acute—for example heavy duty truckoperators and owners are experienced and invested consumers, and havehigh standards for measuring performance against these challenges, andpay close attention to performance against them; heavy duty trucksoperate at high vehicle weights which can increase the difficulty inmeeting these challenges; and heavy duty trucks operate at a high dutycycle (e.g. power throughput as a function of maximum power available)and for long hours, increasing the difficulty and consequences ofmeeting these challenges.

The example system 17100 includes a torque transfer path operativelycoupling the prime mover 17102 to drive wheels, such that motive torquefrom the prime mover 17102 is transferred to the drive wheels. In theexample system 17100, a downstream driveline 17108 receives outputtorque from the transmission 100, and the downstream driveline 17108includes any further devices relative to the transmission 100, forexample a driveline, a deep reduction device, a rear axle gear ordifferential gear, and/or the drive wheels. The components of thedownstream driveline 17108 are non-limiting examples provided only forillustration.

The example system 17100 includes a clutch 106 that selectivelydecouples the prime mover 17102 from the transmission 100 torque path,for example by decoupling the prime mover 17102 from an input shaft 204.The example system 17100 further includes gear meshes 17104, 17112,17114, 17116, 17118, and 17120. The gear meshes control torque transferthrough the transmission 100, and the selection of engaged versusunengaged gear meshes, as well as the gear configurations of the gearmeshes, define the torque transfer multiplication of the transmission100, or the “gear” the transmission 100 is positioned in. In certainembodiments, one or more gear meshes may be configurable in an engagedposition, rotationally coupling the respective shafts, and a neutral orunengaged position, wherein the gears of the gear mesh do notrotationally couple the respective shafts. In certain embodiments, agear mesh may be engaged utilizing a gear coupler, which may or may notfurther include a synchronizer, engagement of an idler gear, or any gearmesh engagement understood in the art. In certain embodiments, a gearmesh may be disengaged or neutral by removal of the gear coupler,allowing respective gears to rotate freely on the respective mountedshaft, removal of a connecting idler gear, or the like. In certainembodiments, the gear meshes 17104, 17112, 17114, 17118, and 17120 areconsistent with embodiments depicted herein, for example in the gear andshaft arrangement depicted in FIG. 9 and the referencing disclosurethereto. Any arrangement of gear meshes, including number of gear meshesin the system, is contemplated herein.

The example system includes a controller 17110, for example at least aportion of the controller 17110 may be included on a TCM 114. Thecontroller 17110 includes and/or is in communication with a number ofsensors and actuators throughout the system 17100. In certainembodiments, the controller 17110 includes and/or is in communicationwith a number of shift actuators 908, 912, 914, 916, for example tocontrol the couplings of the gear meshes 17104, 17112, 17114, 17118, and17120 into a selected configuration. In a further embodiment, thecontroller 17110 controls the shift actuators 908 utilizing two separatevalves for each actuator, a first valve providing actuating force (e.g.pneumatic air pressure into a closed volume to urge a pneumatic pistonin a selected direction) to engage the associated gear coupler to a gearmesh 17104, 17112, 17114, 17118, and 17120, and a second valve providingdisengagement force (e.g. pneumatic air pressure into a second closedvolume to urge the pneumatic piston in a second selected direction) todisengage the associated gear coupler from the gear mesh 17104, 17112,17114, 17118, and 17120. In certain embodiments, a given valve may be adisengaging valve for one shift (e.g. shift actuator 908 “forward”disengages gear mesh 17112) and an engaging valve for a second shift(e.g. shift actuator 908 “forward” engages gear mesh 17104).Additionally or alternatively, the controller 17110 may engage a neutralposition for one or more actuators 908, 912, 914, 916, for example byproviding pressure from both sides of a pneumatic piston.

The example system 17100 includes a main shaft, such as a first mainshaft portion 804 and/or a second main shaft portion 806, and an outputshaft 926. The output shaft 926, in certain embodiments, is coupleableto the main shaft 804, 806 utilizing a gear set 17106, which may be aplanetary gear arrangement (e.g. reference FIG. 31), or any other gearmeshing arrangement to selectively couple the main shaft 804, 806 to theoutput shaft 926. In certain embodiments, the transmission 100 includesa countershaft 902 (or more than one countershaft), which performstorque transfer functions in the transmission 100.

In certain embodiments, the system 17100 includes one or more sensors toprovide system operating parameters. The number and selection of sensorsdepends upon the parameters determined for the system 17100, and furtherdepends upon the availability of information from outside the system,such as on a datalink (private or public, such as J1939, a vehicle areanetwork, or the like), a network communication, or available on aportion of the controller 17110 that is outside the scope of the system17100, but that provides parameters to the system 17100, such as storingparameters in a non-transient computer readable medium. Example andnot-limiting sensors in the system 17100 (not shown), include speedsensors for one or more shafts (e.g. input shaft, output shaft, one ormore countershafts, and/or the main shaft), a rail speed and/or railposition sensor (e.g. shift actuator position), an air supply pressuresensor, a TCM temperature sensor, a grade sensor (e.g. to providevehicle grade information), an oil pressure sensor, a clutch positionsensor, a solenoid temperature sensor (e.g. for one or more solenoidsassociated with actuators in the system), a vehicle mass sensor, aclutch temperature sensor, a service brake position sensor (e.g.on/off), a service brake pressure sensor (e.g. applied pressure and/orcontinuous position), an accelerator request sensor (e.g. acceleratorpedal position), a prime mover torque sensor (e.g. engine torque at theflywheel or other location), and/or a prime move speed sensor. One ormore of the described sensors may be a virtual sensor calculated fromother parameters, and/or one or more of the described sensors may be outof scope of the system, with information, if utilized, passed to thecontroller 17110. Any or all of the listed sensors may not be present incertain embodiments of the system 17100, and in certain embodimentsother sensors not listed may be present as described throughout thedisclosure. Wherever a parameter is described and/or utilized in thepresent disclosure, the parameter may be provided by an appropriatesensor, or otherwise made available without a sensor in the system17100.

Referencing FIG. 60, an example system 17200 is depicted havingactuating hardware schematically depicted for a number of shiftactuators 908, 912, 914, 916. Without limitation, the system 17200 iscompatible with the system 17100, although the system 17200 may beimplemented separately with any compatible transmission 100. The examplesystem 17200 includes the controller 17110 operationally coupled to anumber of actuators, including a number of shift actuator valves 17214and a friction brake valve 17216. In the example of FIG. 60, each shiftactuator 908, 912, 914, 916 includes a closed volume—e.g. 17204, 17206,17208, and 17210 are referenced in FIG. 60—on each side of therespective shift actuator, for example where the shift actuator is apneumatic piston responsive to pressure in the respective closed volumeto urge the shift actuator in a direction such as engaging ordisengaging of a gear mesh. For example, each shift actuator may beshift fork or claw associated with a gear coupler, whereupon the gearcoupler engages or disengages the selected gear mesh. In the example ofFIG. 60, two separate valves are associated with each shift actuator908, 912, 914, 916 to allow independent control of each shift actuator908, 912, 914, 916. Additionally, the friction brake 922 is operativelycoupled to a closed volume 17212, such that pressure provided in theclosed volume 17212 urges the friction brake 922 to engage acountershaft 902, thereby providing for a braking mechanism to slowand/or stop the countershaft 902. The example system 17200 includes anair pressure source 17202, whereby operation of the valves 17214, 17216applies source air to the respective closed volume. In the embodiment ofFIG. 60, the actuators are pneumatic, although in certain embodiments,aspects of the present disclosure are compatible with alternateactuators for one or more of the actuators, including without limitationpneumatic, hydraulic, and/or electrical actuators. An example system17200 further includes the closed volumes 17204, 17206, 17208, 17210 asshift rails, providing a structure for the closed volume and for theshift actuator 908, 912, 914, 916 to travel in a controlled path. One ormore rails may be shared, for example where actuators 908, 912, 914, 916do not require independent control, although in certain embodiments eachactuator is included on a separate shift rail. The example system 17200provides for control of all shift actuators and the friction brake froma common air source 17202.

In certain embodiments, the valves 17214, 17216 herein for the shiftactuators, the valve 17216 for the friction brake 922, and/or the valve17302 (reference FIG. 61) are provided as binary valves—for example thevalves having a position of fully open or fully closed. Binary valveshave a number of advantages, including lower cost, high repeatability,simpler control, and simplified characterization of flow ratedetermination. However, binary valves provide for lower controlcapability than multiple-position valves (e.g. a valve having a discretenumber of potential opening positions) and/or continuously capableposition valves (e.g. valves having a continuous range between open andclosed, and/or a sufficiently large number of potential values betweenopen and closed to be considered similar to a continuously capablevalve). Valves having multiple possible actuating positions are moreexpensive, and provide control complexities such as characterization ofthe flow rate through the valve—for example a model or look-up table,pressure drop measurement of the valve, and/or other complexities aregenerally introduced to provide realization of the capabilities of suchvalves. Embodiments disclosed herein may utilize any type of valve, andcertain features included herein overcome the challenges of utilizing alower cost and capability binary valve for one or more actuating valves,or for all of the actuating valves. In certain embodiments, one or moreactuating valves, or all of the actuating valves, may be a highercapability valve, and certain features included herein are neverthelessbeneficial for higher capability valves as will be apparent to one ofskill in the art having the benefit of the present disclosure.

Referencing FIG. 61, an example system 17300 depicts hardwareschematically having actuating hardware for a clutch actuator 1002. Theexample system 17300 is compatible with the systems 17100, 17200, and incertain embodiments is illustrated separately to clarify thedescription. However, the system 17300 may be included on a transmission100 having one or both of the systems 17100, 17200, and/or may beseparately provided on a standalone system 17300. In the embodiment ofFIG. 61, the controller 17110 is operatively coupled to a clutchactuator valve 17302, which couples the clutch actuator 1002 to an airsource 17202, thereby urging the clutch actuator 1002 to open or closethe clutch 106, depending upon the clutch logic, such as normally-open(e.g. disengaged) or normally-closed (e.g. engaged). In certainembodiments, the clutch actuator 1002 is a pneumatically operated clutchactuator 1002, which may have a near zero dead volume, and/or which maybe a linear clutch actuator (e.g. reference FIG. 10 and the referencingdescription). The system 17300 is compatible with the system 17100,17200, for example to provide all actuators for the clutch, shifting,and friction brake, with a common air source 17202. Further, the systems17100, 17200, 17300 provide for a compact actuation system controllableby a centralized controller 17110, for example to provide for anintegrated actuator housing 112, with independent control of eachactuator in the system 17100, 17200, 17300.

Certain logical groupings of operations herein, for example methods orprocedures of the current disclosure, are provided to illustrate aspectsof the present disclosure. Operations described herein are schematicallydescribed and/or depicted, and operations may be combined, divided,re-ordered, added, or removed in a manner consistent with the disclosureherein. It is understood that the context of an operational descriptionmay require an ordering for one or more operations, and/or an order forone or more operations may be explicitly disclosed, but the order ofoperations should be understood broadly, where any equivalent groupingof operations to provide an equivalent outcome of operations isspecifically contemplated herein. For example, if a value is used in oneoperational step, the determining of the value may be required beforethat operational step in certain contexts (e.g. where the time delay ofdata for an operation to achieve a certain effect is important), but maynot be required before that operation step in other contexts (e.g. whereusage of the value from a previous execution cycle of the operationswould be sufficient for those purposes). Accordingly, in certainembodiments an order of operations and grouping of operations asdescribed is explicitly contemplated herein, and in certain embodimentsre-ordering, subdivision, and/or different grouping of operations isexplicitly contemplated herein.

Referencing FIG. 62, an example procedure 17400 includes an operation17402 to provide a first opposing pulse, the first opposing pulseincluding a first predetermined amount of air above an ambient amount ofair in a first closed volume, where pressure in the first closed volumeopposes movement of a shift actuator in a shift direction. Apredetermined amount of air above an ambient amount of air includes,without limitation, an amount of air estimated, predicted, or calibratedto produce a given pressure in a closed volume, and may be adjusted asthe closed volume changes (e.g. in response to movement of an actuatorsuch as a shift actuator, friction brake actuator, and/or clutchactuator). The pressure may be an indicated pressure (e.g. based on asystem response, and not a measured pressure), a gauge pressure, and/oran absolute pressure. An ambient amount of air is a nominal amount ofair, and may be an amount of air corresponding to actual ambient airpressure under the current operating conditions of the system, anormalized amount of air (e.g. correlated to sea level or anotherselected pressure), an amount of air present before an actuator beginsmovement, or any other nominal amount of air selected for the system.

The procedure 17400 further includes an operation to provide a firstactuating pulse, the first actuating pulse including a secondpredetermined amount of air above an ambient amount of air in a secondclosed volume, where pressure in the second closed volume promotesmovement of the shift actuator in the shift direction. In certainembodiments, the second predetermined amount of air is determined inresponse to a velocity of the shift actuator and a target velocity ofthe shift actuator. The determination of the second predetermined amountof air in response to the velocity of the shift actuator and the targetvelocity of the shift actuator may be open loop (e.g. calibrations ofthe second predetermined amount of air that in testing or modelingdemonstrate performance according to the target velocity) and/oraccording to feedback such as a shift actuator velocity and/or positionvalue tracked over time.

The operations 17402 and 17404 may be performed in any order, with theoperation 17402 preceding the operation 170404, or the operation 17404preceding the operation 17402. The dynamics of the shift actuator inresponse to actuating and opposing pressure, the desired achievedvelocity of the shift actuator, and/or the differential pressureprovided by the actuating pulse and the opposing pulse determine thetiming and amounts of air provided by the first actuating pulse and thefirst opposing pulse.

The provision of the first opposing pulse allows for the first actuatingpulse to move an actuator (e.g. a shift actuator on a rail) at aselected velocity, which may be higher than a controllable velocity withonly an actuating pulse present, and/or further improves repeatabilityof the actuator movement. The procedure 17400 further includes anoperation 17406 to release pressure in the first closed volume and thesecond closed volume in response to determining a shift completion event(e.g. upon determining an open loop schedule for pressure pulsing iscomplete, upon a shift rail position sensor detecting the shift actuatorin the engaged position for a gear mesh, and/or upon determining thatrelated shaft speeds have reached an expected speed ratio for the gearmesh). The operation 17406 to release pressure may include opening avent valve (not shown), allowing pressure to decay, shutting off asource pressure valve (not shown) and opening actuator valves with thesource pressure valve closed, and/or any other operations to releasepressure in the closed volumes.

In certain embodiments, the operation 17404 to provide the firstactuating pulse includes an operation to provide the first actuatingpulse as two split pulses, where a first one of the two split pulses issmaller than a first one of the two pulses. The provision of the firstactuating pulse as two split pulses improves repeatability of the shiftactuation, and can be utilized to confirm movement of the shift actuatorbefore targeting a shift actuator target velocity for engaging theshift. An example operation includes a second one of the two splitpulses includes an amount of air substantially equal to the firstpredetermined amount of air. In the example the first one of the twopulses may not be sufficient to overcome the opposing pulse or toachieve a desired shift actuator velocity, but the net amount of thefirst one of the two pulses above the substantially equal opposing pulseand second one of the split actuating pulse provides the selecteddriving force for the shift actuator. The amount of air that is asubstantially equal amount of air is determinable by the context and theconfiguration of the application of the shift rail actuator. Forexample, an amount of air having the same mass and/or the same number ofmoles, and amount of air provided by a similar actuation time of thevalve actuators, and amount of air provided by similar actuation of thevalve actuators but compensating for flow differences (e.g. effectiveflow areas between the valve providing the actuation pulse and theopposing pulse), and/or an amount of air compensated for the closedvolumes on each side to provide a similar pressure on each side are allcontemplated examples of substantially equal amounts of air.Additionally or alternatively, differences in the driving force requiredto move the shift actuator in the actuating or opposing direction mayprovide for differing air amounts that nevertheless provide similardriving forces in each direction, and are therefore such air amounts aresubstantially equal for the purpose of the present disclosure.

In certain embodiments, the first one of the two split pulses includesan amount such as: between one-tenth and one-fourth of a total amount ofair provided by the two split pulses, less than 40% of a total amount ofair provided by the two split pulses, less than 33% of a total amount ofair provided by the two split pulses, less than 25% of a total amount ofair provided by the two split pulses and/or less than 20% of a totalamount of air provided by the two split pulses.

The described ratios between the first and second split portions of thefirst actuating pulse are non-limiting examples, and one of skill in theart, having the benefit of the disclosures herein and informationordinarily available when contemplating a particular system, can readilydetermine air amounts for the first actuating pulse, whether provided astwo split pulses, and the first opposing pulse. Certain considerationsin determining the first amount of air, the second amount of air, thesplitting of the actuation pulse, and the amounts of the split actuationpulse include the volume of the system for each of the closed volumes(e.g. rail size, position, distance from actuating valve, etc.), thepressure of the air source, the dynamics of air pressure generation inthe actuating or opposing portion of the rail (e.g. the valve flowdynamics, temperature of the system, delay times between commanding avalve and valve response, friction of the shift actuator in eachdirection, and/or the current position of the shift actuator). Thecurrent position of the shift actuator may affect at least the volume ofthe closed volume on the actuating or opposing side of the actuator, thedynamics of pressure generation in the closed volume, and/or theresistance of the shift actuator to movement (e.g. engaging detents orother features during travel, changing lubrication environment, and/orcompressing or expanding a changing volume of air on each side of theshift actuator). It will be understood that corrections for these andother elements can be readily provided with basic system testing of thetype ordinarily performed, through modeling and/or laboratory testingand calibration into the predetermined air amounts, and/or by providingfor a feedback loop such as a rail position feedback, air pressurefeedback, or similar measured parameter, and adjusting the pulses inreal time to ensure desired behavior of the shift actuator.

An air pulse, as described herein, should be understood broadly. An airpulse includes the provision of a determined amount of air in adetermined amount of time, a scheduled opening time for a valve, afeedback based air amount such as a pressure increase amount in aselected volume, and/or a number of moles or a mass of air to beprovided, and the like. A pulse may be provided in a single actuation(e.g. open a valve for a predetermined period of time), as multipleactuations that combine to create an equivalent actuation to the airpulse, a predetermined amount of air specific to another parameter suchas the changing volume of the closed volume, which may includeadditional air amounts to maintain the predetermined air amount, and/ora feedback based response of the actuator to correct for unmodeledfactors or noise factors in the system, wherein further responses fromthe feedback are included as the air pulse. Additionally oralternatively, where a pulse is described herein, for example in singlepulses or split pulses, as a pulse width modulated actuation of thevalve, and or amounts of air provided over time, it is understood that acontinuously modulated valve may be used with a shaped trajectory toprovide the behavior described herein. For example, where a binary(on/off) valve is used with split pulses for the first actuating pulse,and where a first split portion is smaller than and precedes a largersecond split portion, an embodiment includes at least two distinctpulses provided by a binary valve. Alternatively or additionally,embodiments that include a single shaped pulse providing a similar airover time characteristic (e.g. a low rate of air, with or without a gappreceding a higher rate of air) are also contemplated herein as twodistinct notional pulses, even if the air provision is not completelystopped between pulses. Similarly, a first split portion may include anumber of actuations to provide the first split portion amount of air inthe first selected time frame, and a second split portion may include adistinct number of actuations to provide the second split portion amountof air in the second selected time frame. Any air pulse operations,and/or air amount operations described herein may be similarly replacedby such equivalent operations, although the description may describespecific air pulses for clarity of description.

In certain embodiments, the first opposing pulse is performed at least100 milliseconds (msec) before the first actuating pulse. Additionallyor alternatively, the first actuating pulse may be performed before thefirst opposing pulse, and/or the actuating and opposing pulse may beperformed at the same time and/or overlap. For example, in certainembodiments, it may be desired that no two actuating valves are open atthe same time (e.g. to provide for a predictable air source pressure),and a portion of each of the first opposing pulse and the firstactuating pulse may be performed in alternating (in equal or non-equalincrements) and overlapping fashion. In certain embodiments, more thanone actuating valve may be opened at the same time, and the system mayinclude an air source with sufficient air delivery that pressure effectson the multiple valves open can be ignored, and/or the system mayinclude compensation for the multiple valves and the effect on thesource air pressure at the transmission inlet, shift rail system inlet,and/or at individual actuating valves of the system. In certainembodiments, the first actuating pulse is performed within a 200 msecwindow.

Referencing FIG. 63, an example procedure 17500 includes an operation17502 to determine that a synchronizer engagement is imminent, and theoperation 17402 to provide the first opposing pulse is performed inresponse to the imminent synchronizer engagement. For example, theoperation 17502 includes determining the imminent synchronizerengagement in response to a shift rail position value (e.g. from a shiftrail position sensor), a time of the first actuating pulse being active,and/or a modeled rail response based upon the first actuating pulse(measured or open loop), an actuating valve position, and/or a pressurefeedback in the shift rail closed volume on the actuating side. Incertain embodiments, for example for a shift wherein the gear couplerdoes not have a synchronizer, the operation 17502 may be to determine agear coupler engagement rather than a synchronizer engagement. Theoperations are otherwise similar for a synchronized or non-synchronizedsystem for procedure 17500. The provision 17402 of the first opposingpulse before the synchronizer (or gear coupler) begins engagement allowsfor a controlled and/or selected engagement velocity of the shiftactuator, reducing noise, part wear, and providing for smoothershifting. In certain embodiments, the shift actuator velocity is cut to50% or more from a traversing velocity before the provision 17402 of thefirst opposing pulse. In embodiments where the first opposing pulse isprovided before the first actuating pulse, the operation 17402 mayinclude provision of second opposing pulse to slow the shift actuatorbefore engagement. In certain embodiments, the shift actuator velocityis reduced to about 300 mm/sec, and/or to a value lower than 600 mm/sec,by the opposing pulse provided before the engagement. The velocityreduction amount is determined by the responsiveness of the actuators,the pressure of the air source, the ability to detect imminentengagement with high accuracy, precision, and time resolution, andsimilar parameters that will be understood to one of skill in the art.The selected velocity reduction depends upon the materials and requiredtolerances of the gear coupler and/or synchronizer, the desired life ofparts involved, expected shift frequency, and time allotted to a shiftevent. Accordingly, one of skill in the art having the benefit of thedisclosures herein and knowledge ordinarily available when contemplatinga particular system, can select a desired shift actuator traversevelocity before engagement, and a desired imminent engagement reductionvalue, as required for the particular system, and select appropriatesensors or actuators to enable the desired shift actuator velocity andimminent engagement reduction value according to the principlesdescribed herein.

In certain embodiments, the procedure 17500 further includes anoperation 17504 to determine that a synchronizer is in an unblockedcondition. In certain embodiments, where the synchronizer engages and isbringing the shaft speeds together (“sitting on the block”), a timeperiod elapses where the shift actuator does not progress as gear teethare blocked from engaging as the shafts on each side of the gear meshapproach the same speed. When the shafts approach the same speed, theteeth are unblocked (“come off the block”) and the shift actuator willprogress to engage the gear. Example operations 17504 to determine thata synchronizer is in an unblocked condition include determining that aspeed differential between engaging shafts is lower than an unblockingthreshold value, determining that a speed differential between engagingshafts is within a predetermined unblocking range value, determiningthat a synchronizer engagement time value has elapsed (e.g. time on theblock elapses), and/or determining that a shift actuator position valueindicates the unblocking condition (e.g. shift actuator with appliedpressure begins to move toward engagement again).

The example procedure 17500 further includes an operation 17506 toprovide a second opposing pulse before or as the shift actuator movesafter unblocking and into full engagement. In certain embodiments, theopposing resistance to the shift actuator drops dramatically when thesynchronizer is unblocked, and can provide an undesired closing speed tofull engagement. In certain embodiments, for example where a firstopposing pulse is provided before the actuation pulse and/or before theopposing pulse provided in operation 17402, the opposing pulse providedin operation 17506 is a third opposing pulse.

In certain embodiments, any of the actuating pulses and/or opposingpulses are provided as a pulse-width-modulated (PWM) operation. A PWMoperation, as disclosed herein, should be interpreted broadly andreferences any provision of air over multiple actuation events toprovide a predetermined amount of air and/or an adjusted amount of airover a period of time, and/or to support another parameter in the system(e.g. a shift actuator velocity, a pressure value, or the like). A PWMoperation ordinarily indicates a predetermined period of operation, witha selected duty cycle (e.g. “on-time” percentage of the actuator withinthe period, which can be varied to provide selected response), and suchoperations are contemplated herein as a PWM operation. Additionally oralternatively, a PWM operation as used herein includes an adjustment ofthe PWM period, for example, and without limitation, to support minimumor maximum actuator on-times where an otherwise indicated duty cycle mayexceed the period and/or indicate a valve actuation on-time below aselected minimum on-time for the valve. Additionally, while PWM-typeoperations are ordinarily beneficial for binary actuation (e.g. anon-off actuator valve), PWM-type operations may similarly be provided bya continuously capable actuator (e.g. an actuator capable of providingmultiple opening values, and/or a continuous range of opening values),for example, and without limitation, to support feedback on systemresponse to added air amounts and allow for real-time adjustment of thepredetermined air amounts. In certain embodiments, PWM-type operationsallow for binary actuators to provide actuation approximating acontinuous actuator, but PWM-type operations can provide benefits foractuators providing multiple opening vales and/or a continuous range ofopening values according to the principles described herein.

Referencing FIG. 64, a procedure 17600 includes an operation 17602 todetermine a shift actuator position value, and an operation 17604 tomodify a duration of the first actuating pulse in response to the shiftactuator position value. The operation 17604 includes changing thesecond predetermined amount of air, and/or modulating the firstactuating pulse in response to the shift actuator position value (e.g.via a PWM operation or other modulation mechanism). Example andnon-limiting shift actuator position values include: a quantitativeposition description of the shift actuator; a quantitative velocitydescription of the shift actuator; and/or a shift state descriptionvalue corresponding to the shift actuator. Example and non-limitingshift state description values include a neutral position, a neutraldeparture position, a synchronizer engagement approach position; asynching position; a synchronizer unblock position; an engaged position;and/or a disengaging position. In certain embodiments, the determinationof the shift state description value include utilizing a shift actuatorposition value to determine the shift state description, observing oneor more system operating conditions that correlate to the shift state,and/or utilizing predetermined open loop timing values during shiftoperations to determine the shift state. Example and non-limiting systemoperating conditions that may correlate to one or more shift statesinclude one or more shaft speeds in the system, a rate of change of oneor more shaft speeds in the system, shift actuator response (e.g.movement rates, positions), a pressure value in the system (e.g.pressure on an actuating or opposing closed volume for the shiftactuator), a rate of change of a pressure value in the system, anactuator position (e.g. providing air or not), and/or a source airpressure value. The operations of procedure 17600 may be utilized,without limitation, to perform or modify operations 17404 to provide thefirst actuating pulse, and/or may be provided as independent operationsduring a shift procedure.

An example procedure includes the operation 17404 to provide the firstactuating pulse as a shaped air provision trajectory. For example, andwithout limitation, the shaped air provision trajectory includes anamount of air over time having a desired shape to the air provision, andthe actuating valve provides the shaped air provision trajectory as amodulated valve operation, PWM valve operation, continuously capablevalve operation over time, and/or operation from a valve having multipleair flow rate capabilities to create the air provision trajectory. Incertain embodiments, the first actuating pulse includes at least oneoperation to open and close a binary pneumatic valve.

Referencing FIG. 65, a procedure 17700 includes an operation 17702 todetermine at least one shaft speed value, an air supply pressure value,at least one temperature value, and/or a reflected driveline inertiavalue. The example procedure 17700 further includes an operation 17704to determine the predetermined first air amount in response to the atleast one shaft speed value, the air supply pressure value, the at leastone temperature value, and/or the reflected driveline inertia value.Additionally or alternatively, the example procedure 17700 furtherincludes an operation 17706 to determine a timing of the predeterminedfirst air amount in response to the at least one shaft speed value, theair supply pressure value, the at least one temperature value, and/orthe reflected driveline inertia value. In certain embodiments, theprocedure 17700 may be utilized, without limitation, to perform ormodify operations 17402 to provide the first opposing pulse. Theprocedure 17700 determines, without limitation, an appropriate timeand/or air amount for the opposing pulse to provide a selected velocityreduction in the shift actuator before engagement of the associated gearcoupler with the gear mesh during a shift engagement. In certainembodiments, a shaft speed related to the gear mesh for engaging isutilized for the shaft speed, and the operations 17704, 17706 utilizethe shaft speed to determine the predetermined first air amount and thetiming of the first predetermined air amount. Additionally oralternatively, the operations 17704, 17706 utilize a temperature valueto determine the predetermined first air amount and the timing of thefirst predetermined air amount. The shaft speed affects both the shiftactuator velocity to reach the engagement position and/or the desiredvelocity to engage the gear mesh, and accordingly utilization of theshaft speed allows for compensation to provide desired engagementparameters. In certain embodiments, a temperature value in the systemaffects the shift actuator velocity—for example and without limitationaffecting friction drag or other velocity affecting parameters (e.g.lubrication temperature, pressure response, and/or differentialexpansion of sliding parts)—and temperature compensation helps providedesired engagement parameters. The temperature value may be anytemperature that at least partially correlates with a relevanttemperature, and without limitation, TCM temperature, oil temperature,ambient temperature, and/or solenoid temperatures may be utilized fortemperature compensation. In certain embodiments, a shaft speed relatedto the gear mesh is not available in the system (e.g. for a main shaftshift where main shaft speed is not available), and a compensated offsetspeed may be utilized. In one example, a main shaft speed is notavailable, and an output shaft speed correlated to the main shaft speed,for example utilizing an air supply pressure value as a compensatingparameter, is utilized in the operations 17704, 17706.

In certain embodiments, the operations 17704, 17706 further includedetermining predetermined first air amount and/or the timing of thepredetermined first air amount in response to the reflected drivelineinertia value. Example and non-limiting values for the reflecteddriveline inertia include a perceived and/or effective inertia of thedriveline. Example operations to determine the reflected drivelineinertia include determining the reflected driveline inertia in responseto a launch having a known torque value and an observed accelerationrate, and/or determining vehicle data from a datalink (e g vehicle mass,driveline configuration including one or more of a rear axle ratio,drive wheel radius, etc.). Additionally or alternatively, a reflecteddriveline inertia value may be estimated or assumed, and systemresponses observed to determine if the estimated or assumed reflecteddriveline inertia is higher, lower, or about equal to the actualreflected driveline inertia value. The reflected driveline inertia valueaffects the desired shift time, engagement forces, and transientbehavior of the torque transfer path through the transmission, andaccordingly the operations 17704, 17706 can be utilized, in certainembodiments, to provide for increased or decreased shift response time,and/or higher or lower shift actuator velocity at the gear meshengagement.

In certain embodiments, the procedures 17600, 17700 to determine thefirst predetermined air amount, the second predetermined air amount,and/or a timing of the first predetermined air amount, include adjustingat least one of the first actuating pulse and/or the first opposingpulse in response to the shift actuator position value. In certainembodiments, the adjusting includes interrupting the first actuatingpulse and/or the first opposing pulse to synchronize pressure decay inthe first closed volume and the second closed volume. Additionally oralternatively, the adjusting includes interrupting the first actuatingpulse and/or the first opposing pulse to coordinate pressure decay inthe first closed volume and the second closed volume. Synchronizingpressure decay should be understood broadly, and includes at leasttiming the pressure decay in each volume such that the shift actuator isnot disengaged from the gear, such that the shift actuator does notprovide excessive engagement force to the gear coupler and/orsynchronizer during pressure decay, and/or includes timing the pressuredecay in each volume such that the pressure is reduced at about the sametime (e.g. within about 1 second apart, within about 200 msec apart,and/or within about 100 msec). Coordinating pressure decay should beunderstood broadly, and includes at least providing for pressure decayin each volume in light of the pressure decay in the other volume,coordinating the pressure decay such that the shift actuator does notdisengage the gear coupler and/or synchronizer during pressure decay,coordinating the pressure decay such that engagement and/ordisengagement forces from the shift actuator are kept below a thresholdvalue, and/or coordinating the pressure decay such that a pressuredifferential on the shift actuator is kept below a threshold value.

In certain embodiments, operation 17604 to modify the duration of thefirst actuation pulse includes modulating the first actuation pulse,and/or further includes reducing the second predetermined amount of airin response to the shift actuator position value being a shift statedescription value, and/or reducing the first actuating pulse in responseto the shift state description value indicating a synching phase of theshift actuator (e.g. where a synchronizer is sitting on the block). Incertain embodiments, reducing the first actuating pulse includeslimiting an air pressure build-up in the second closed volume. Theoperation 17604 thereby reduces engagement forces on the synchronizerand/or gear mesh, reducing part wear and resulting in a smoothershifting operation.

Referencing FIG. 66, an example procedure 17800 includes an operation17802 to provide a third opposing pulse, the third opposing pulseincluding a third predetermined amount of air above an ambient amount ofair in a third closed volume, where pressure in the third closed volumeopposes movement of a second shift actuator in a shift direction, anoperation 17804 to provide a second actuating pulse, the secondactuating pulse including a fourth predetermined amount of air above anambient amount of air in a fourth closed volume, where pressure in thefourth closed volume promotes movement of the second shift actuator inthe shift direction. The procedure 17800 further includes an operation17806 to determine a second shift completion event, and an operation17808 to release pressure in the third closed volume and the fourthclosed volume in response the operation 17806 determining the secondshift completion event. An example system includes the controller 17110performing the procedure 17800 such that not more than one actuatingvalve is open simultaneously, for example performing a first shift eventaccording to procedures 17400, 17500, 17600, 17700 before performing asecond shift event according to procedure 17800, and/or interleavingshift events such that no two valves are open at the same time.Procedure 17800 is additionally modifiable according to any one ofprocedures 17500, 17600, 17700, and/or any other disclosures herein.Additionally or alternatively, more than one actuator valve may beopened at the same time, and operations herein modified to compensatefor pressure changes, the air source 17202 capable of providingsufficient flow that pressure compensation is not necessary, and/or morethan one separate air source 17202 provided in the system.

Referencing FIG. 67, an example procedure 17900 includes an operation17902 to engage a friction brake to a countershaft of a transmission, anoperation 17904 to track an engaged time of the friction brake, anoperation 17906 to determine a target release time for the frictionbrake, an operation 17908 to determine a release delay for the frictionbrake in response to the engaged time, and an operation 17910 to commanda release of the friction brake in response to the release delay and thetarget release time.

In certain embodiments, an engaged time of the friction brake providesfor a build-up of pressure in the friction brake actuator closed volume17212. Accordingly, a delay is exhibited after a command to disengagethe friction brake is performed (e.g. the friction brake actuator valveis closed) before the friction brake disengages. In certain embodiments,the operation 17908 includes determining the release delay bydetermining a pressure decay value in a friction brake actuation volume,for example utilizing a model, open loop calibration, or otherdetermination of pressure decay in response to friction brake on-time.In certain embodiments, a friction brake on-time exceeding a saturationvalue may result in a fixed relationship between the on-time and therelease delay, and for on-time values below the saturation value, arelationship between the on-time and the release delay is calculated,calibrated, and/or included as a pre-determined relationship in to thecontroller 17110. In certain embodiments, the operation 17908 includesdetermining a pressure in the friction brake actuation volume. Incertain embodiments, the operation 17906 includes determining a speeddifferential between the countershaft and an engaging shaft, anddetermining the target release time in response to the speeddifferential, for example where the friction brake is utilized to bringthe countershaft speed down to be close to the speed of the engagingshaft to provide for a quicker, smoother, and/or quieter shift event.Example and non-limiting engaging shafts include an output shaft, a mainshaft, and/or an input shaft. In certain embodiments, the operation17906 includes determining lumped driveline stiffness value, anddetermining the target release time further in response to the lumpeddriveline stiffness value. The lumped driveline stiffness value, withoutlimitation, includes the dynamic torsional response of the driveline,and affects the dynamic response of the system (e.g. how fast the systemwill speed up or slow down) and/or the desired speed differentialimposed for a shift engagement. Accordingly, the inclusion of drivelinestiffness in the friction brake release allows for better control of thespeed differential at engagement and/or quicker, smoother, and/orquieter shifting. In certain embodiments, the target gear ratio forengagement is included in determining the lumped driveline stiffnessvalue. In certain embodiments, the operation 17906 includes determiningthe target release time further in response to the target gear ratiovalue, rather than including the target gear ratio value in the lumpeddriveline stiffness value—for example where the lumped drivelinestiffness value is determined independently of the target gear ratio,and inclusion of the target gear ratio compensates the lumped drivelinestiffness value without the target gear ratio. In certain embodiments,the operation 17906 includes determining a friction brake disengagementdynamic value, and determines the target release time further inresponse to the friction brake disengagement dynamic value. Example andnon-limiting aspects of the friction brake disengagement dynamic valueinclude the friction brake response of the return spring that disengagesthe friction brake (including wear or degradation thereof), compensationfor temperature effects on friction brake disengagement and/ortemperature effects shift actuator speeds and/or shaft speeds (e.g.slower responding parts in cold temperatures may provide for a shorterengagement of the friction brake during a shift, limiting unnecessaryutilization of the friction brake and corresponding losses in efficiencyand slower shifting). In certain embodiments, the operation 17906includes determining a vehicle speed effect, and determining the targetrelease time further in response to the vehicle speed effect. Exampleand non-limiting vehicle speed effects include a current vehicle speed,an estimated vehicle speed at a gear engagement time, a vehicleacceleration rate, and/or a vehicle deceleration rate. For example andwithout limitation, a vehicle in a accelerating or deceleratingenvironment may result in changing shaft speeds, resulting in a distincttarget speed for the countershaft from a nominal shift otherwise plannedfor current operating conditions, and the example controller 17110responds by targeting a countershaft speed according to the speed targetat the time of shift engagement, resulting in a greater or lesserengagement of the friction brake during the shift.

Referencing FIG. 68, an example apparatus 18000, including thecontroller 17110 in the example of FIG. 68, includes a backlashindication circuit 18002 that identifies an imminent backlash crossingevent 18006 at a first gear mesh. The apparatus 18000 further includes ameans for reducing engagement force experienced by the first gear meshin response to the backlash crossing event 18006.

Certain non-limiting examples of the means for reducing engagement forceexperienced by the first gear mesh in response to the backlash crossingevent 18006 are described following. An example means for reducingengagement force experienced by the first gear mesh further includes thecontroller 17110 disengaging the first gear mesh during at least aportion of the backlash crossing event, for example by commanding ashift actuator to move a synchronizer and/or gear coupler to disengagethe first gear mesh in response to the imminent backlash crossing event18006. In certain embodiments, the controller 17110 provides apre-loaded amount of air to the actuator(s) to position the shiftactuator to a neutral position. The shift actuator may move thesynchronizer and/or gear coupler to the neutral position, and/or thesynchronizer and/or gear coupler may be locked in to the gear mesh untilthe backlash crossing event occurs, whereupon during the zero torqueportion of the backlash crossing, the pre-loaded shift actuator willslide the synchronizer and/or gear coupler out of gear, preventingbounce, oscillation, and/or other undesirable behavior during thebacklash crossing. Accordingly, the first gear mesh is therebydisengaged during at least a portion of the backlash event. Additionallyor alternatively, the controller 17110 provides a command to disengage aclutch during at least a portion of the backlash crossing event, and/orto slip the clutch (e.g. reduce clutch engagement torque until theclutch is not in lock-up) during at least a portion of the backlashcrossing event. The disengagement and/or slipping of the clutchmitigates the torsional forces experienced during the backlash event,allowing the gear mesh to settle on the other side of the backlash (e.g.from drive side to coast side engagement, or from coast side to driveside engagement) without experiencing negative consequences to smoothoperation of the transmission 100, noticeable effects by the driver oroperator, and/or mitigating these.

The example apparatus 18000 includes the backlash indication circuit18002 identifying the imminent backlash crossing event 18006 bydetermining that a gear shift occurring at a second gear mesh is likelyto induce the backlash crossing event at the first gear mesh. Forexample, in a shift of just a forward gear (e.g. at the input shaft, ora “splitter” shift), where the rearward gear is to remain in the sameengagement after the shift, a backlash crossing event may occur at therearward gear under certain operating conditions, which may be predictedaccording to the current side of the rearward gear mesh (e.g. coast sideor drive side), the vehicle speed and acceleration, and/or the speeds ofthe input shaft, countershaft, and/or prime mover. The example backlashindication circuit 18002 determines the imminent backlash crossing event18006 for the first gear mesh (rearward in the example) in response tothe gear shift at the second gear mesh (forward gear mesh in theexample). The example apparatus 18000 further includes a means forreducing engagement force experienced by the first gear mesh. Exampleand non-limiting means for reducing engagement force experienced by thefirst gear mesh include disengaging the first gear mesh during at leasta portion of the gear shift—for example a first gear mesh pre-loadcircuit 18004 provides a disengagement pulse command 18008, where ashift actuator responsive to the disengagement pulse command 18008disengages the first gear mesh during at least a portion of the gearshift. An example disengagement pulse command includes a fifthpredetermined amount of air above an ambient amount of air in a fifthclosed volume, and where pressure in the fifth closed volume promotesmovement of the shift actuator in the disengagement direction. Incertain embodiments, the disengagement pulse command 18008 furtherincludes a sixth predetermined amount of air above an ambient amount ofair in a sixth closed volume, where pressure in the sixth closed volumeopposes movement of the shift actuator in the disengagement direction.In the example, the fifth closed volume and sixth closed volume arevolumes on each side of a pneumatic piston comprising a portion of theshift actuator, and where first gear mesh pre-load circuit 18004determines the fifth predetermined amount of air and the sixthpredetermined amount of air such that the shift actuator is urged into aneutral position in response to a release of engagement force. In oneexample, engagement force is released during the backlash crossingevent, eliminating or reducing oscillations, noise, and other negativeeffects of the backlash crossing event with the first gear mesh engaged.In certain embodiments, the time response of determining the imminentbacklash crossing event 18006, providing the disengagement pulse command18008, and/or response of the valve actuators providing the fifthpredetermined air amount and/or sixth predetermined air amount, resultin the disengagement of the first gear mesh on a subsequent backlashcrossing event after a first backlash crossing event (e.g. on a “bounce”after the first backlash crossing). Even where the disengagement occursafter the first backlash crossing event, oscillations, noise, and othernegative consequences of the backlash crossing are reduced.

An example apparatus 18000 includes the backlash indication circuit18002 further identifying the imminent backlash crossing event 18006 byperforming at least one operation such as: determining that an imminentrotational direction of the first gear mesh in a transmission is anopposite rotational direction to an established rotational direction ofthe first gear mesh, determining that a speed change between a firstshaft comprising gears on one side of the first gear mesh and a secondshaft comprising gears on an opposing side of the first gear mesh islikely to induce the backlash crossing event, determining that a gearshift occurring at a second gear mesh is likely to induce the backlashcrossing event at the first gear mesh, determining that a transmissioninput torque value is at an imminent zero crossing event, and/ordetermining that a vehicle operating condition is likely to induce thebacklash crossing event.

Referencing FIG. 69, an example system 18100 is depicted schematicallyto illustrate interactions of certain aspects of the system 18100. Thesystem 18100 includes and/or interacts with a prime mover 17102providing motive torque. The system 18100 further includes a torquetransfer path 18102 operatively coupling the motive torque to drivewheels 17108. The torque transfer path 18102 in the example system 18100depicts certain aspects of a simplified torque transfer path 18102. Theexample torque transfer path 18102 includes a clutch 106 thatselectively decouples the prime mover 17102 from an input shaft 204 ofthe torque transfer path 18102, where the input shaft 204 isoperationally downstream of the clutch 106. The torque transfer path18102 further includes a first gear mesh 18106 and a second gear mesh18108, where each gear mesh 18106, 18108 includes an engaged and aneutral position, and where both gear meshes in the engaged positioncouple the input shaft 204 to the drive wheels 17108, and where eithergear mesh 18106, 18108 in the neutral position decouples the input shaft204 from the drive wheels 17108. The coupling depicted in the examplesystem 18100 is through the countershaft 902, and a lumped mainshaft/output shaft component 18104. However, other torque transfer pathsare contemplated herein, and the system 18100 is not limited to theparticular components defining the torque transfer path 18102. Thesystem 18100 includes a first shift actuator (not shown) thatselectively operates the first gear mesh 18106 between the engaged andneutral position, and a second shift actuator (not shown) thatselectively operates the second gear mesh 18108 between the engaged andneutral position. It is understood that additional shift actuators maybe present, for example where a gear mesh 18106, 18108 is accessible bymore than one shift actuator. The system further includes a controller17110 that performs certain operations to ensure that unintended vehiclemotion is not experienced at the drive wheels 17108. More detaileddescriptions of operations of the controller 17110 are set forth in thedescription referencing FIG. 70. The first and second gear meshes may beany gear meshes in the system 18100 where, when both gear meshes areintended to be disengaged, and at least one of the gear meshes issuccessfully disengaged, torque transfer from the prime mover 17102 tothe drive wheels 17108 is prevented. In one example, even if one of thegear meshes is inadvertently engaged if intended to be disengaged (e.g.where one of the gear meshes has a failed position sensor erroneouslyreporting that the gear mesh is disengaged when it is actually engaged),torque transfer from the prime mover 17102 to the drive wheels 17108 isprevented. In certain embodiments, the first gear mesh and/or the secondgear mesh may include more than one gear mesh—for example the first orsecond gear mesh may include: all gear meshes between the input shaftand the countershaft (splitter gears), all gear meshes between thecountershaft and the main shaft (main box gears), or all gear meshesbetween the main shaft and the output shaft (range gears). In certainembodiments, a first one of these is the first gear mesh, and a secondone of these is the second gear mesh.

Referencing FIG. 70, a system 18200 includes a controller 17110 having avehicle state circuit 18202 that interprets at least one vehicleoperating condition 18206, a neutral enforcement circuit 18204 thatprovides a first neutral command 18208 to the first shift actuator and asecond neutral command 18210 to the second shift actuator, in responseto the vehicle operating condition indicating that vehicle motion is notintended. Example and non-limiting vehicle operating conditions 18206include: an engine crank state value, a gear selection value, a vehicleidling state value, and/or a clutch calibration state value. Forexample, during engine cranking and/or certain gear selection value (e.gNeutral or Park), vehicle operating guidelines and/or regulations mayindicate that vehicle movement, and/or transition of prime mover torqueto the drive wheels, is not desired and/or not allowed. In certainembodiments, a vehicle idling condition may indicate that vehiclemovement is not desired and/or not allowed. In certain embodiments, forexample during a clutch calibration event to determine clutch torque toposition parameters (reference FIG. 71 and the referencing description),the transmission 100 may be performing maneuvers wherein vehiclemovement is not desired and/or not allowed. In certain embodiments,vehicle state circuit 18202 further determines the vehicle operatingcondition 18206 as a vehicle stopped condition, for example from adatalink state command, an operating condition of the vehicle, and/orone or more parameter values (vehicle speed, brake pedal position, brakepedal pressure, accelerator position or torque request, engagement of avehicle state inconsistent with movement such as a hood switch, PTOdevice, or the like), and where the neutral enforcement circuit 18204further provides the first neutral command 18208 and the second neutralcommand 18210 in response to the vehicle stopped condition. Theprovision of the first neutral command 18208 and the second neutralcommand 18210, and the response of the shift actuators to enforce twoseparate neutral positions in the transmission 100, prevents a singlepoint failure in the transmission 100, such as a rail position sensor orstuck shift actuator, from allowing unintended vehicle motion.

The example system 18200 includes the controller 17110 further having ashift rail actuator diagnostic circuit 18212 that diagnoses properoperation of at least one shift rail position sensor (not shown) inresponse to a vehicle speed value 18214. The vehicle state circuit 18202further interprets at least one failure condition 18218, and provides avehicle stopping distance mitigation value 18216 in response to the atleast one failure condition 18218. Example and non-limiting failureconditions 18218 include mission disabling failures wherein normaloperations of the transmission 100 and/or vehicle systems are precluded,for example but not limited to a loss in ability to shift one or moregears, a loss in power to a primary controller, where a secondarycontroller is capable to operate the clutch, loss of a datalink orcommunication with the vehicle system and/or engine, or othercatastrophic failure wherein control of the clutch 106 is maintained,but other control is lost. The controller 17110 further includes aclutch override circuit 18220 that provides a forced clutch engagementcommand 18222 in response to the vehicle stopping distance mitigationvalue 18216. The vehicle stopping distance mitigation value 18216includes, without limitation, and indication that operations of theclutch to mitigate increased vehicle stopping distance resulting fromthe failure condition 18218 are to be performed. An example clutchoverride circuit 18220 further provides a forced clutch engagementcommand 18222 in response to the vehicle stopping distance mitigationvalue 18216 and further in response to at least one value such as: amotive torque value representative of the motive torque, an engine speedvalue representative of a speed of the prime mover, an acceleratorposition value representative of an accelerator pedal position, aservice brake position value representative of a position of a servicebrake position, a vehicle speed value representative of a speed of thedrive wheels, and/or a service brake diagnostic value. In certainembodiments, the forced clutch engagement command 18222 provides forengagement of the clutch when the vehicle speed, motive torque,accelerator position, service brake position, and/or vehicle speed aresuch that stopping distance is not increased by engagement of theclutch. For example, in conditions where engine braking or otheroperations will be able to reduce speed during clutch engagement, theforced clutch engagement command 18222 provides for clutch engagement.When conditions change such that clutch engagement may increase thestopping distance, for example when the engine idle governor isproviding motive torque that overcomes other stopping forces, and/orother stopping forces without consideration to the service brake, theforced clutch engagement command 18222 indicates to open the clutch. Incertain embodiments, the service brake may be in a faulted condition(e.g. service brake diagnostic value indicates that the service brakeposition is unknown), and accordingly the service brake logic can beadjusted accordingly—e.g. service brake position may be disregarded whenthe service brake is faulted, and/or the faulted service brake may be afailure condition 18218 according to the vehicle operating guidelines,settings of the vehicle and/or engine, and/or applicable regulations.

Referencing FIG. 71, an example system 18300 includes a clutch 106 thatselectively decouples a prime mover 17102 from an input shaft 204 of atransmission 100, a progressive actuator 1002 operationally coupled tothe clutch 106, where a position of the progressive actuator 1002corresponds to a position of the clutch 106. The system 18300 furtherincludes a controller 17110 that provides a relationship between aposition of the progressive actuator (and clutch) and a clutch torquevalue (e.g. engagement torque of the clutch). More detailed descriptionsof the operations of the controller 17110 are provided in FIG. 72 andthe disclosure referencing FIG. 72.

Referencing FIG. 72, an apparatus 18400 includes a controller 17110including: a clutch characterization circuit 18402 that interprets aclutch torque profile 18410, the clutch torque profile 18410 providing arelation between a position of the clutch and a clutch torque value(e.g. an engagement torque of the clutch in response to a position ofthe clutch and/or a position of the progressive actuator). The apparatus18400 further includes a clutch control circuit 18404 that commands aposition of the progressive actuator in response to a clutch torquereference value 18412 and the clutch torque profile 18410. For example,an algorithm in the controller 17110 provides a clutch torque request asa clutch torque reference value 18412 to the clutch control circuit18404. The clutch characterization circuit 18402 further interprets aposition 18414 of the progressive actuator and an indicated clutchtorque 18434, and updates the clutch torque profile 18410 in response tothe position 18414 of the progressive actuator and the indicated clutchtorque 18434.

The example apparatus 18400 includes the clutch torque profile 18410including a first clutch engagement position value 18416, and where theclutch control circuit 18404 further utilizes the first clutchengagement position value 18416 as a maximum zero torque position 18420.For example, in response to receiving a zero clutch torque referencevalue 18412, and/or to receiving a “clutch disengaged” command, theclutch control circuit 18404 positions the clutch actuator at a positionbelow that indicated by the maximum zero torque 18420. The exampleclutch characterization circuit 18402 further interprets the clutchtorque profile 18410 by performing a clutch first engagement positiontest 18424.

The example apparatus 18400 includes the clutch torque profile 18410including a second clutch engagement position value 18418, and where theclutch control circuit 18404 further utilizes the second clutchengagement position value 18418 as a minimum significant torque position18422. For example, in response to receiving a non-zero clutch torquereference value 18412, and/or to receiving a “clutch engaged” command,the clutch control circuit 18404 positions the clutch actuator at aposition equal to or greater than that indicated by the minimumsignificant torque 18422. The example clutch characterization circuit18402 further interprets the clutch torque profile 18410 by performing aclutch second engagement position test 18426.

Referencing FIG. 73, an example procedure 18500 to perform the clutchfirst engagement position test 18424 includes an operation 18502 todetermine that an input shaft speed is zero, and if the input shaftspeed is not zero, an operation 18504 to bring the input shaft speed tozero. The procedure 18500 further includes an operation 18506 (e.g.performed by the clutch control circuit 18404) to positioning the clutchat the first engagement position value 18416, and an operation 18508 tocompare an acceleration of the input shaft speed 18428 to a firstexpected acceleration value 18430 of the input shaft speed to determinewhether the selected first clutch engagement position value 18416utilized in the test is consistent with the maximum zero torque value18420—for example if an expected torque response is achieved, or if thetorque response is greater (reduce the position value 18416 in asubsequent test) or lower (increase the position value 18416 in asubsequent test). The initial first clutch engagement position value18416 utilized may be a calibrated value, an expected value, a valueadjusted according to a clutch wear value 18440, a currently utilizedfirst clutch engagement position value 18416, a currently utilizedmaximum zero torque value 18420, and/or a value selected according to amost recent successful completion of the procedure 18500. In certainembodiments, the procedure 18500 includes an operation 18510 to repeatthe clutch first engagement test a number of times (e.g. 2 times, 3times, up to 10 times, and/or as many times as possible in an allottedtime to perform). Example and non-limiting examples include performingthe test during a cranking event, during an idling event, and/or duringa vehicle launch event. The procedure 18500 further includes anoperation 18512 to process the first clutch engagement position value18416 to provide the maximum zero torque value 18420. Example andnon-limiting operations 18512 include using a most repeatable value ofthe position value 18416, an average of several position values 18416, amost reliable position value 18416 (e.g. test conditions were cleanduring the test), and/or incrementing or decrementing a previous maximumzero torque value 18420 in a direction indicated by the updated positonvalue 18416 (e.g. to limit a rate of change of the maximum zero torquevalue 18420 for control or rationality purposes). In certainembodiments, the apparatus 18400 includes a friction brake controlcircuit 18406 responsive to commands from the clutch characterizationcircuit 18402 to support operations of the procedure 18500, such asoperation 18504 to stop the input shaft. In certain embodiments, theclutch control circuit 18404 is responsive to commands from the clutchcharacterization circuit 18402 to control the clutch actuator position18414 during operations of the procedure 18500.

Referencing FIG. 74, an example procedure 18600 to perform the clutchsecond engagement position test 18426 includes an operation 18602 todetermine that an input shaft speed is zero, and if the input shaftspeed is not zero, an operation 18604 to bring the input shaft speed tozero. The procedure 18600 further includes an operation 18606 (e.g.performed by the clutch control circuit 18404) to positioning the clutchat the second engagement position value 18418, and an operation 18608 tocompare an acceleration of the input shaft speed 18428 to a secondexpected acceleration value 18432 of the input shaft speed to determinewhether the selected second clutch engagement position value 18418utilized in the test is consistent with the minimum significant torquevalue 18422—for example if an expected torque response is achieved, orif the torque response is greater (reduce the position value 18418 in asubsequent test) or lower (increase the position value 18418 in asubsequent test). The initial second clutch engagement position value18418 utilized may be a calibrated value, an expected value, a valueadjusted according to a clutch wear value 18440, a currently utilizedsecond clutch engagement position value 18418, a currently utilizedminimum significant torque value 18422, and/or a value selectedaccording to a most recent successful completion of the procedure 18600.In certain embodiments, the procedure 18600 includes an operation 18610to repeat the clutch second engagement test a number of times (e.g. 2times, 3 times, up to 10 times, and/or as many times as possible in anallotted time to perform). Example and non-limiting examples includeperforming the test during a cranking event, during an idling event,and/or during a vehicle launch event. The procedure 18600 furtherincludes an operation 18612 to process the second clutch engagementposition value 18418 to provide the minimum significant torque value18422. Example and non-limiting operations 18612 include using a mostrepeatable value of the position value 18418, an average of severalposition values 18418, a most reliable position value 18418 (e.g. testconditions were clean during the test), and/or incrementing ordecrementing a previous minimum significant torque value 18422 in adirection indicated by the updated positon value 18418 (e.g. to limit arate of change of the minimum significant torque value 18422 for controlor rationality purposes). In certain embodiments, the apparatus 18400includes a friction brake control circuit 18406 responsive to commandsfrom the clutch characterization circuit 18402 to support operations ofthe procedure 18600, such as operation 18604 to stop the input shaft. Incertain embodiments, the clutch control circuit 18404 is responsive tocommands from the clutch characterization circuit 18402 to control theclutch actuator position 18414 during operations of the procedure 18600.

Referencing FIG. 75, an illustration 18700 depicts an example clutchtorque profile 18410 and an example updated clutch torque profile 18410a. In the illustration 18700, a first maximum zero torque value 18420 isdepicted (defined as a clutch position 18420 corresponding to a maximumzero torque 18702 in the example), and a first minimum significanttorque value 18422 (defined as a clutch position 18422 corresponding toa minimum significant torque 18704 in the example). In the illustration18700, the first maximum zero torque value 18420, the first minimumsignificant torque value 18422, and the corresponding clutch torqueprofile 18410 represent a clutch torque profile 18410 at a first pointin time. The clutch torque profile 18410 in the example is a 2-D lookuptable of a plurality of torque-position points, with linearinterpolation between points. However a clutch torque profile 18410 mayinclude any representation and/or number of points, including acorrelating equation or the like. Between the first maximum zero torquevalue 18420 and the first minimum significant torque value 18422, theclutch torque profile 18410 is depicted as linearly interpolatingbetween the position values. However, the torque correlation between thefirst maximum zero torque value 18420 and the first minimum significanttorque value 18422 may alternatively be held at one or the other of thefirst maximum zero torque value 18420 and the first minimum significanttorque value 18422, for example to ensure that a positive torque requestutilized a value greater than the first minimum significant torque value18422, to ensure that a low or zero torque request utilized a valuelower than the maximum zero torque value 18420, or for any otherconsiderations. The illustration 18700 further depicts a maximum clutchtorque value 18706, for example a maximum possible torque for theclutch, a torque value which, if it is achievable, the clutch isconsidered to be properly functioning, and/or a torque value including amaximum value of a given clutch torque profile 18410, 18410 a.

The illustration 18700 further includes a second maximum zero torquevalue 18420 a, for example as determined in procedure 18500 at a secondpoint in time, and a second minimum zero torque value 18422 a, forexample as determined in procedure 18600 at the second point in time. Inthe example 18700, it is noted, for illustrative purposes, that theminimum zero torque value 18422 has not shifted 18714 as greatly as themaximum zero torque value 18420 shift 18712. In the illustration 18700,the second clutch torque profile 18410 a above the second minimumsignificant torque value 18422 a is shifted an amount equal to the shift18714—e.g. the higher torque engagement points have been shifted inposition space by the distance of the shift 18714 in the minimumsignificant torque value, and the shape of the curve in the highertorque engagement points has been held constant. In certain embodiments,where information correlating to the clutch position and torque forhigher engagement points is available, the change in the clutch torqueprofile 18410 can be more complex, and/or informed by such information.In certain embodiments, the shape of the clutch torque profile 18410 athigher engagement points can be informed and updated by the clutch wearvalue 18440, and/or by high torque clutch engagement opportunitiespresented according to vehicle operating conditions and expectedbehaviors providing an indicated clutch torque 18434 for those hightorque clutch engagement positions.

In certain embodiments, the clutch characterization circuit 18402further determines that the clutch is operating in a wear-through mode18438 in response to at least one of the first engagement position value18416 and the second engagement position value 18418 changing at a rategreater than a clutch wear-through rate value 18442, and/or a clutchwear circuit 18408 determining a clutch wear value 18440, and where theclutch wear value 18440 exceeds a wear-through threshold value. Anexample clutch wear circuit 18408 determines the clutch wear value 18440in response to clutch operating values 18436, such as a clutchtemperature value, a clutch power throughput value, and/or a clutch slipcondition. In certain embodiments, the clutch wear circuit 18408increments a wear counter in response to the clutch temperature, theclutch power throughput, and/or the clutch slip condition. In certainembodiments, the clutch power and slip condition exhibit a firstresponse to clutch wear, and accordingly a first slope of wear below ahigh wear temperature line, and exhibit a second response to clutchwear, and accordingly a second slope of wear (higher than the firstslope) at or above the high wear temperature line. The high weartemperature line depends upon the materials of the clutch, and isdeterminable with simple wear testing of the type ordinarily performedon a contemplated system given a clutch configuration with a known type.

Referencing FIG. 76, an example procedure 18800 to determine clutch wearincludes an operation 18802 to determine a clutch temperature value, aclutch power throughput value, and a clutch slip condition. Theprocedure 18800 further includes an operation 18804 to accumulate aclutch wear index determined in response to the clutch temperaturevalue, the clutch power throughput value, and the clutch slip condition.In certain embodiments, the clutch wear index accumulates linearly withclutch power throughput, linearly with clutch slip condition (e.g.proportional to a slipping rate) and/or accumulates at zero or a definedlow accumulation rate with zero slip, and accumulates non-linearly withtemperature, including a non-linear function with temperature, and/or afirst linear function below a high wear temperature value and at asecond higher slope linear function above the high wear temperatureline. The clutch temperature value may be a sensed temperature value(e.g. an optical temperature sensor, or any other temperaturedetermination known in the art), and/or may be a modeled temperatureand/or virtual sensor based temperature.

The example procedure 18800 further includes an operation 18806 toprovide a clutch diagnostic value in response to the clutch wear index.Example and non-limiting clutch wear values includes providing a clutchwear fault value (e.g. failed, passed, worn, suspect, etc.),incrementing a clutch wear fault value (e.g. incrementing a faultcounter in response to the wear index, and/or triggering a fault whenthe fault counter exceeds a threshold value), communicating the clutchdiagnostic value to a data link (e.g. to provide the wear indicator to afleet or service personnel, to provide the wear indicator to anotheraspect of a system for consideration—e.g. an engine, vehicle, routemanagement device, etc.), and/or providing the clutch diagnostic valueto a non-transient memory location accessible to a service tool. Theclutch wear diagnostic value may light a dashboard lamp or provide othernotification, or may remain available on a controller 17110 to beaccessible upon request or in a fault snapshot. In certain embodiments,the procedure 18800 includes an operation 18808 to provide the clutchwear index and/or a clutch wear value 18440 to the clutchcharacterization circuit 18402 and utilized in determining the clutchtorque profile 18410.

Referencing FIG. 71, an example system 18300 includes a clutch 106 thatselectively decouples a prime mover 17102 from an input shaft 204 of atransmission, a progressive actuator 1002 operationally coupled to theclutch, where a position of the progressive actuator 1002 corresponds toa position of the clutch 106, and a means for providing a consistentlock-up time of the clutch. The lock-up time of the clutch includes atime commencing with a clutch torque request time 18908 and ending witha clutch lock-up event 18910.

Certain non-limiting examples of the means for providing a consistentlock-up time 18912 of the clutch are described following. ReferencingFIG. 77, an apparatus 18900 includes a controller 17110 having a clutchcontrol circuit 18404, where the clutch control circuit 18404 commands aposition 18414 of the progressive actuator in response to a clutchtorque reference value 18412 and the clutch torque profile 18410 toachieve the consistent lock-up time 18912 of the clutch. In certainembodiments, the progressive actuator includes a linear clutch actuator,and/or a pneumatic actuator having a near zero dead air volume.

An example apparatus 18900 to provide the consistent lock-up time 18912of the clutch further includes the controller 17110 having a launchcharacterization circuit 18902, where the launch characterizationcircuit 18902 interprets at least one launch parameter 18904 such as: avehicle grade value, a vehicle mass value, and/or a drivelineconfiguration value. Example and non-limiting driveline configurationvalues include a target engagement gear description, a reflecteddriveline inertia value, and/or a vehicle speed value. An exampleapparatus 18900 further includes the clutch control circuit 18404further commanding the position 18414 of the progressive actuator inresponse to the at least one launch parameter 18904 to achieve theconsistent lock-up time 18912 of the clutch. In certain embodiments, theclutch control circuit further 18404 further commands the position 18414of the progressive actuator in response to a clutch slip feedback value18906. An example system further includes the clutch torque request time18908 including at least one request condition such as: a service brakepedal release event, a service brake pedal decrease event, a gearengagement request event, and/or a prime mover torque increase event. Incertain embodiments, the clutch lock-up time 18912 is measured from theclutch torque request time 18908 to the clutch lock-up event 18910. Incertain embodiments, the clutch lock-up event 18910 includes a clutchslip value 18906 being lower than a clutch lock-up slip threshold value18914.

In certain embodiments, the controller 17110 includes the clutch controlcircuit 18404 further providing commanding the position 18414 of theprogressive actuator to maintain the clutch slip feedback value 18906between a slip low threshold value and a slip high threshold value. Incertain embodiments, the slip low threshold value and the slip highthreshold value are a rate of change of the clutch slip, such thatclutch slip is reduced within a controlled rate of change to provide asmooth transition to lock-up. In certain embodiments, the rate of changeof the clutch slip is reduced at a rate to achieve the consistentlock-up time 18912 of the clutch. In certain embodiments, the variationsin the rate of change of the clutch slip induced by input shaftoscillations are compensated—for example by applying a filter on theinput shaft speed value (used in determining the clutch slip feedbackvalue 18906, in certain embodiments) that removes the oscillationfrequency component from the input shaft speed. An example filterincludes a notch filter at a selected range of frequencies, which may bedetermined according to known characteristics of the input shaft, and/ordetermined by a frequency analysis of the input shaft speed (e.g. afast-Fourier transform, or the like) to determine which frequencies theoscillation is affecting In certain embodiments, the clutch controlcircuit further includes enhanced response to an error value such as adifference between the rate of change of the clutch slip value and atarget rate of change, and/or being outside the slip low threshold valueand/or slip high threshold value. In certain embodiments, enhancedresponse can include proportional control and/or gain scheduling ofclutch torque commanded in response to the error value.

Referencing FIG. 78, an example procedure 19000 to determine a vehiclemass value includes an operation 19002 to interpret a motive torquevalue, a vehicle grade value, and a vehicle acceleration value. Theprocedure 19000 further includes an operation 19004 to determine threecorrelations: a first correlation between the motive torque value andthe vehicle grade value; a second correlation between the motive torquevalue and the vehicle acceleration value; and a third correlationbetween the vehicle grade value and the vehicle acceleration value. Theprocedure 19000 further includes an operation 19006 to adapt anestimated vehicle mass value, an estimated vehicle drag value, and anestimated vehicle effective inertia value in response to the threecorrelations. In certain embodiments, the vehicle mass value is anestimate of the vehicle mass (e g current mass—as the procedure 19000 incertain embodiments is responsive to the current vehicle mass), and thevehicle effective inertia value is a description of the inertia of thepowertrain (e.g. engine, transmission, and/or driveline components) andmay include torque input to get the driveline up to speed, startinginertia, and/or acceleration inertia (e.g. contributions to accelerationin response to acceleration or deceleration of the driveline. In certainembodiments, the vehicle drag value includes air resistance, internalfriction, and/or rolling resistance. In certain embodiments, lumpedvalues are used to estimate the vehicle mass value, the estimatedvehicle drag value, and the vehicle effective inertia value. In certainembodiments, initial estimates are utilized, and the adapting operation19006 includes utilizing observed current (or recently stored history)vehicle conditions (acceleration, speed, and contributions fromtraversing a grade) to identify the net forces and anticipatedacceleration (e.g. according to F=MA), and to increment the vehicle massvalue, the vehicle drag value, and the vehicle effective inertia valuein a manner to fit the observed current vehicle conditions. Theprocedure 19000 further includes an operation 19010 to determine anadaptation consistency value, and in response to the adaptationconsistency value, to adjust an adaptation rate of the adapting 19006,and an operation 19008 to iteratively perform the preceding operations(19002, 19004, 19006, 19010, 19014) to provide an updated estimatedvehicle mass value. Other estimates, such as the vehicle effectiveinertia value and/or the estimated vehicle drag value, may be updated inconjunction with the estimated vehicle mass value. In certainembodiments, the adapting 19006 includes performing the adapting atoperating conditions where parameters can be isolated—for example atvehicle launch, acceleration or deceleration on a level grade, and/orsteady climbing or coasting on a grade. However, the adapting 19006 maybe performed at any vehicle operating conditions.

In certain embodiments, the procedure 19000 further includes theadapting 19006 slowing and/or halting the adapting of the estimatedvalues in response to an operation 19004 determining the firstcorrelation, the second correlation, and the third correlation having anunexpected correlation configuration. Example unexpected correlationincludes a negative correlation for the first correlation and/or thesecond correlation, and/or a positive correlation for the thirdcorrelation. For example, a relationship between the torque and grade isexpected to be positive and linear, a relationship between the torqueand acceleration is expected to be positive and linear, and arelationship between grade and acceleration is expected to be negativeand linear. An example operation 19006 includes adapting by increasingor continuing adapting the estimated values in response the operation19004 determining the first correlation, the second correlation, and thethird correlation have an expected correlation configuration. Forexample, where the correlations continue to have an expectedrelationship, it is anticipated that the adapting will converge oncorrect estimates for the vehicle mass value, the vehicle drag value,and the vehicle effective inertia value, and the adapting is continuedor the step size is increased. Where the correlations do not have theexpected relationship, it is not anticipated that the adapting willconverge on correct estimates for the vehicle mass value, the vehicledrag value, and the vehicle effective inertia value, and the adapting ishalted or the step size is decreased.

The procedure 19000 further includes an operation 19010 to adjust theadaptation rate in operation 19006 in response to the estimates changingmonotonically and/or holding at a consistent value. For example, wherethe adaptation operation 19006 continues to move at least one estimatein the same direction, with the other estimates also continuing to movein a same direction and/or being held constant, the adaptation 19006 isanticipated to be moving correctly, and to be farther from the correctestimates. Where the adaptation 19006 experiences a change in directionfor one or more estimates, the adaptation is expected to be close to thecorrect converged value. In certain embodiments, the adaptation 19006 isfurther responsive to a linearity of the correlations, and the linearityof the correlations, in addition to the sign of the correlations (e.g.positive for torque-grade and torque-acceleration, and negative forgrade-acceleration), is anticipated to be a measure of the likelihood ofsuccessful convergence of the estimates to correct values. Accordingly,where correlations are linear, the operation 19006 increases or holdsthe step sizes, and where one or more correlations are non-linear, theoperation 19006 decreases step sizes and/or halts adaptation 19006 untillinearity is restored. In certain embodiments, the operation to 19010 toadjust the adaptation rate is performed in response to a changing thedirection of an estimate being a change greater than a threshold changevalue. In certain embodiments, the procedure 19000 includes an operation19014 to implement the adaptation step size change in response to theperformance against expectations of the correlations and the consistencyof the estimate changes. The example procedure 19000 includes anoperation 19016 to provide estimates, including at least a vehicle massestimate, to other aspects of a controller 17110. In certainembodiments, the procedure 19000 continues indefinitely, to remainresponsive to changes in vehicle mass. In certain embodiments, theprocedure 19000 includes both providing estimates 19016 and iteratingthe operations 19002, 19004, 19006, 19010, 19014. In certainembodiments, the procedure 19000 halts after converging, and/or haltsfor a given operation cycle (e.g. a trip or drive cycle) afterconverging, and is performed again for a next operation cycle.

Referencing FIG. 79, an example procedure 19100 includes an operation19102 to determine that a shift rail position sensor corresponding to ashift actuator controlling a reverse gear is failed. The procedure 19100further includes an operation 19104 to determine that a gear selectionis active requesting and/or requiring operations of the shift actuator,and in response to the gear selection and the failed shift rail positionsensor, performing operations, in order: an operation 19106 to commandthe shift actuator to a neutral position, an operation 19108 to confirmthe neutral position by commanding a second shift actuator to engage asecond gear, where the second shift actuator is not capable of engagingthe second gear unless the shift actuator is in the neutral position,and an operation 19108 to confirm the second shift actuator has engagedthe second gear, and an operation 19110 to command the shift actuatorinto the gear position in response to the gear selection. In certainembodiments, the procedure 19100 includes performing the operations19104, 19106, 19108, 19110 each time the shift actuator controlling thereverse gear is utilized.

The example procedure 19100 includes the operation 19102 to determinethe shift rail position sensor is failed by determining the shift railposition sensor is failed out of range. In certain embodiments, a sensorfailed out of range is readily detectable according to the electricalcharacteristics of the sensor—for example where a sensor is shorted toground, shorted to high voltage, and/or providing a voltage value, A/Dbit count, or other value that is outside the range of acceptable valuesfor the sensor.

In certain embodiments, referencing FIG. 80, an operation 19102 todetermine the shift rail position sensor is failed includes determiningthe shift rail position sensor is failed in range, for example where thesensor is providing a valid value, but the value does not appear tomatch the position of the shift actuator. The operation 19102 includesan operation 19202 to command the shift actuator to the neutralposition, an operation 1904 to command the shift actuator to an engagedposition, and an operation 19206 to determine if the shift actuatorengaged position is detected by the sensor. In response to the operation1906 indicating the shift actuator engaged position is not detected, theoperation 19102 includes an operation 19208 to command the shiftactuator to the neutral position, an operation 19210 to command a secondshift actuator to engage a second gear, where the second shift actuatoris not capable of engaging the second gear unless the shift actuator isin the neutral positon, and an operation 19212 to confirm the secondshift actuator has engaged the second gear. The operation 19102 furtherincludes an operation 19214 to determine the shift rail position sensoris failed in range in response to the neutral position being confirmed,and an operation 19216 to determine a shift rail operated by the shiftactuator is stuck in response to the neutral position not beingconfirmed. The procedure 19100 and operation 19102 thereby provide amechanism to continue to operate a shift actuator having an out of rangefailed sensor, provide a mechanism to identify a failed sensor inresponse to an in range failure without the provision of redundant oradditional sensors, provide a mechanism to respond to a shift actuatorin an unexpected position (e.g. neutral) at a start-up time, and providea mechanism to avoid unintended movement in a wrong direction (e.g.forward or reverse) with a failed shift actuator position sensor.

Referencing FIG. 81, an example system 19300 includes a transmission 100having a solenoid operated actuator 19302, and a controller 17110 thatoperates the solenoid 19304 within a temperature limit of the solenoid19304. Further details of operations of the controller 17110 aredescribed in relation to FIG. 82 following. Referencing FIG. 82, anapparatus 19400 includes the controller 17110 including a solenoidtemperature circuit 19402 that determines an operating temperature 19404of the solenoid, a solenoid control circuit 19406 that operates thesolenoid in response to the operating temperature 19404 of the solenoid,and where the solenoid control circuit 19406 operates the solenoid 19304by providing an electrical current 19410 to the solenoid 19304, suchthat a target temperature 19412 of the solenoid 19304 is not exceeded.

In certain embodiments, the solenoid temperature circuit 19402determines the operating temperature 19404 of the solenoid according toa determination of the solenoid temperature in response to an electricalcurrent value 19414 of the solenoid and an electrical resistance value19416 of the solenoid. The electrical current value 19414 of thesolenoid is a determined current value of the solenoid 19304, and maydiffer from the electrical current 19410 commanded or provided to thesolenoid 19304, especially in transient operation and/or where thesolenoid temperature is elevated and/or where the solenoid 19304 isdegraded or aged. For example, the solenoid control circuit 19406, incertain embodiments, provides the electrical current 19410 by providinga voltage to the solenoid 19304 (e.g. system voltage, a TCM outputvoltage, and/or a PWM scheduled voltage) according to the electricalcurrent 19410 planned for the solenoid 19304, and the solenoid 19304specific electrical characteristics may exhibit an electrical currentvalue 19414 that differs from the electrical current 19410 planned. Incertain embodiments, the solenoid control circuit 19406 provides theelectrical current 19410 to the solenoid 19304 such that the electricalcurrent 19410 is achieved (within the voltage limits of the TCM voltageoutput), for example by feedback on a measured current value andresponse on the TCM voltage output (which may be variable and/oradjusted in a PWM manner, which may be filtered to provide a steady orpseudo-steady voltage to the solenoid 19304), and accordingly in steadystate the electrical current 19410 commanded will be achieved for suchembodiments. Additionally or alternatively, the solenoid 19304 incertain embodiments includes a coil having inductive properties, and thevoltage from the solenoid 19304 may exhibit dynamic voltage (andtherefore current) behavior. Accordingly, in certain embodiments, thesolenoid temperature circuit 19402 in certain embodiments may determinethe operating temperature 19404 of the solenoid in response to a dynamiccharacteristic of the solenoid, such as a voltage rise characteristic,an RMS voltage exhibited by the solenoid over a predetermined timeperiod (e.g. over a time window beginning at a predetermined time afteractivation and ending at a predetermined time later), according to atime characteristic at which a specified voltage is reached, and/oraccording to a time characteristic at which a specified voltage increaseis achieved (e.g. the time from 3.0 V to 5.0 V, the time from 1.0 V to5.2 V, and/or any other voltage window). In certain embodiments, thesolenoid temperature circuit 19402 determines the solenoid temperaturein response to a steady state voltage 19420 achieved by the solenoid.Any operations to determine the operating temperature 19404 of thesolenoid 19304 are contemplated herein. In certain embodiments, thesolenoid 19304 exhibits a resistance response to temperature, forexample according to a known characteristic of the metal in the solenoidcoil (e.g. similar to a thermistor or resistance temperature detectorused as a temperature sensor). In certain embodiments, aresistance-temperature curve 19418 is calibrated and stored on thecontroller 17110 and accessible to the solenoid temperature circuit19402.

In certain embodiments, the solenoid temperature circuit 19402 furtherdetermines the operating temperature 19404 of the solenoid in responseto an electrical current value 19414 of the solenoid and an electricalresistance value 19416 of the solenoid. In certain embodiments, one orboth of the electrical current value 19414 and the electrical resistancevalue 19416 may be calculated or measured by the solenoid temperaturecircuit 19402. In certain embodiments, the solenoid temperature circuit19402 determines the voltage drop across the solenoid 19304—for exampleat a voltage high and ground pin on the TCM, and in certain furtherembodiments the solenoid temperature circuit 19402 determines a currentacross the solenoid, for example with a solid state current meter in thevoltage provision circuit to the solenoid 19304. Any other structuresand/or operations to determine the electrical current value 19414 andthe electrical resistance value 19416 of the solenoid 19304 arecontemplated herein. In certain embodiments, the solenoid temperaturecircuit 19402 further determines the operating temperature 19404 of thesolenoid in response to a thermal model 19422 of the solenoid, forexample including a cooldown estimate of the solenoid 19302 to providean estimated temperature of the solenoid 19302 when active voltage isnot being provided to the solenoid 19302. In certain embodiments, thevoltage provided to the solenoid may be varied to assist in determiningthe operating temperature 19404 of the solenoid, for example to providea voltage value that is at a known temperature determination point forthe solenoid, and/or to move the current determination value of thesolenoid into a higher resolution area of the resistance-temperaturecurve 194118.

In certain embodiments, the system includes the solenoid operatedactuator 19302 having a reduced nominal capability solenoid 19304. Forexample, and without limitation, the reduced nominal capability solenoid19304 includes a cheaper material on the solenoid coil (e.g. that mayexhibit increased temperature response and/or that also improvesdetection of the solenoid temperature), a smaller sized solenoidrelative to a nominal solenoid (e.g. where a higher current throughputis enabled by temperature management allowing for reduced amount of coilmaterials, and/or the solenoid can be operated more often and for longerperiods than a nominally designed solenoid, also allowing for a reducedamount of coil materials, and/or allowing for a smaller solenoidfootprint—e.g. due to a smaller housing, more challenging heat transferenvironment to the coil, and/or less mass of material and/or cheapermaterials having a lower heat capacity to provide a reduced heat sinkfor the solenoid). Each of the described capability reductions in thesolenoid can reduce costs of the solenoid and/or reduce the physicalspace required by the solenoid, and one or more of the capabilityreductions is enabled by active thermal management of the solenoid bythe apparatus 19400. In certain embodiments, the solenoid controlcircuit 19406 further operates in response to the operating temperature19404 of the solenoid and the target temperature 19412 of the solenoidby modulating at least one parameter such as: a voltage provided to thesolenoid, a cooldown time for the solenoid, and/or a duty cycle of thesolenoid. Example and non-limiting duty cycles include changing a PWMcharacteristic of the solenoid (e.g. changing a period, frequency,and/or on-time width of the valve actuator 19302 providing air to theclutch, a shift actuator, or the friction brake), adjusting a shiftevent to avoid utilization of the actuator 19302 (e.g. delaying oradjusting a target gear ratio, or adjusting a friction brake utilizationduring a shift, to enable the solenoid 19304 to cool down).

Referencing FIG. 83, an example system 19500 includes a transmission 100having a pneumatic clutch actuator 1002, for example operated by a valve19502 coupling the clutch actuator 1002 to an air source a clutchposition sensor 19504 configured to provide a clutch actuator positionvalue 19610 (reference FIG. 84), and a controller 17110 the determineswhether a clutch actuator leak is present. Further details of operationsof the controller 17110 are provided in the description referencing FIG.84 following.

Referencing FIG. 84, an apparatus 19600 includes a controller 17110having a clutch control circuit 19602 that provides a clutch actuatorcommand 19604, where the pneumatic clutch actuator 1002 is responsive tothe clutch actuator command 19604. The controller 17110 further includesa clutch actuator diagnostic circuit 19606 that determines that a clutchactuator leak 19608 is present in response to the clutch actuatorcommand 19604 and the clutch actuator position value 19610. The examplecontroller 17110 further includes the clutch actuator diagnostic circuit19606 determining the clutch actuator leak 19608 is present in responseto the clutch actuator position value 19610 being below a thresholdposition value 19612 for a predetermined time period 19614 after theclutch actuator command 19604 is active. In certain embodiments, theclutch actuator diagnostic circuit 19606 further determines the clutchactuator leak 19608 is present in response to the clutch actuatorposition value 19612 being below a clutch actuator position trajectoryvalue 19616, the clutch actuator position trajectory value 19616including a number of clutch actuator position values 19618corresponding to a number of time values 19620. In certain embodiments,the clutch actuator diagnostic circuit 19606 determines the clutchactuator leak 19608 is present in response to the clutch actuatorposition value 19610 failing to match any one or more, or all, of theclutch actuator position trajectory values 19616; determines the clutchactuator leak 19608 is present in response to the clutch actuatorposition value 19610 meeting or exceeding any one or more, or all, ofthe clutch actuator position trajectory values 19616; and/or determinesa clutch actuator leak 19608 is suspected in response to the clutchactuator position value 19610 failing to match some of the clutchactuator position trajectory values 19616. In certain embodiments, inresponse to the clutch actuator leak 19608 being TRUE or FALSE, and/or asuspected clutch actuator leak 19608, the clutch actuator diagnosticcircuit 19606 may set a fault code, provide the leak or suspected leakto other aspects of the controller 17110, increment or decrement a faultcode, communicate the leak value to a service component (not shown—e.g.a maintenance location, a service location, and/or a fleet agent),and/or store a value indicating the leak value in non-transient memorywhere the stored value is accessible to a service tool.

In certain embodiments, the controller 11710 further includes a sourcepressure sensor 19506 (reference FIG. 83) configured to provide a sourcepressure value 19622, and where the clutch actuator diagnostic circuit19606 further determining the clutch actuator leak 19608 is present inresponse to the source pressure value 19622. In certain embodiments, theclutch actuator threshold position value 19612 and predetermined timeperiod 19614 are determined according to a properly operating clutchactuator and/or a known failed clutch actuator. In certain embodiments,the clutch actuator position trajectory value 19616, including thenumber of clutch actuator position values 19618 corresponding to anumber of time values 19620 are determined according to a properlyoperating clutch actuator and/or a known failed clutch actuator. Incertain embodiments, the clutch actuator diagnostic circuit 19606further determines the clutch actuator leak 19608 is present in responseto the source pressure value 19622 by adjusting one or more of thevalues 19612, 19614, 19616, 19618, 19620, for example increasing a timeor decreasing a distance expectation in response to a low sourcepressure value 19622, and/or decreasing a time or increasing a distanceexpectation in response to a high source pressure value 19622.

Referencing FIG. 85, an example system 19700 further includes atransmission 100 having at least one gear mesh 19702 operatively coupledby a shift actuator, and a controller 17110 that mitigates or clears atooth butt event 19806 (reference FIG. 86) of the gear mesh 19702 andshift actuator 19704. The example system 19700 further includesactuating valves 19706 that control a clutch actuator 1002, a frictionbrake 19712, and/or the shift actuator 19704. The illustrativecomponents to provide pneumatic control of the clutch actuator 1002,friction brake 19712, and/or shift actuator 19704 utilizing an airsource 17202 are non-limiting, and any actuation devices and scheme arecontemplated herein. The gear mesh 19702 is depicted for purposes ofillustration as the countershaft to input shaft gear mesh, however anygear mesh in the transmission 100, and related shift actuator and/orgear coupler or synchronizer, is contemplated herein. Further details ofoperations of the controller 17110 are described following in thedescription referencing FIG. 86.

Referencing FIG. 86, an apparatus 19800 includes a controller 17110having a shift characterization circuit 19802 that determines that atransmission shift operation 19804 is experiencing a tooth butt event19806. An example operation to determine the tooth butt event 19806include a shift engagement time exceeding a threshold time value, amaintained difference in speeds between shafts operationally coupled tothe gear mesh, and/or an amount of time a synchronizer is sitting on theblock exceeding a threshold time. An example controller 17110 furtherincludes a shift control circuit 19808, where the shift control circuit19808 provides a reduced rail pressure 19810 in a shift rail during atleast a portion of the tooth butt event, for example by the controller17110 limiting operations of an air supply valve 19706 to limitengagement pressure of the shift actuator. Accordingly, noise of theshift event, and/or damage or progressive damage to the shift actuator19704 and/or gear mesh 19702 are thereby limited. An example controller17110 includes a clutch control circuit 19812, where the clutch controlcircuit 19812 modulates an input shaft speed 19814 in response to thetooth butt event 19806. An example clutch control circuit 19812modulates the input shaft speed 19814 by commanding a clutch slip event19816 in response to the tooth butt event 19806, thereby disturbing theinput shaft 204 and inducing a modulation in the input shaft speed19814, and assisting in clearing the tooth butt event 19806 condition.An example controller 17110 includes a friction brake control circuit19818, where the friction brake control circuit 19818 modulates acountershaft speed 19820 in response to the tooth butt event 19806, forexample by briefly engaging a friction brake 19712. An examplecontroller 17110 clears the tooth butt event by controlling adifferential speed 19822 between shafts operationally coupled to thegear mesh to a selected differential speed range 19824. The controller17110 utilizes any actuator in the system 19700 to implement thedifferential speed control 19822, including at least the clutch actuator1002, the friction brake 19712, and/or a command to the prime mover17102 for a torque pulse (not shown), which may be coordinated withcontrol of the clutch actuator 1002. Example and non-limiting values forthe selected differential speed range 19824 include at least one speedrange value such as: less than a 200 rpm difference; less than a 100 rpmdifference; less than a 50 rpm difference; about a 50 rpm difference;between 10 rpm and 100 rpm difference; between 10 rpm and 200 rpmdifference; and/or between 10 rpm and 50 rpm difference.

Referencing FIG. 85, an example system 19700 includes a clutch 106 thatselectively decouples a prime mover 17102 from an input shaft 204 of atransmission, a progressive actuator 1002 operationally coupled to theclutch 106, and where a position of the progressive actuator 1002corresponds to a position of the clutch 106. The system 19700 furtherincludes a controller 17110 that disengages the clutch 106 to provide areduced driveline oscillation, improved driver comfort, and/or reducedpart wear. Further details of operations of the controller 17110 aredescribed in the description referencing FIG. 87 following. ReferencingFIG. 87, a controller 17110 includes a clutch control circuit 19812 thatmodulates a clutch command 19902 in response to at least one vehicleoperating condition 19904, and where the progressive actuator 1002 isresponsive to the clutch command 19902. Example and non-limiting vehicleoperating conditions 19904 include a service brake position value, aservice brake pressure value, a differential speed value between twoshafts in a transmission including the clutch 106 and progressiveactuator 1002, and/or an engine torque value. In certain embodiments, adepressed service brake, and/or strongly depressed service brake, cancause vehicle deceleration such that a sudden or a nominal clutchdisengagement (nominal being a selected clutch disengagement rate in theabsence of selected vehicle operating conditions 19904 having valuesthat cause transmission transients in response to a clutchdisengagement) can result in oscillation of transmission components,causing noise, part wear, and/or oscillations that affect the drivelineand drive wheels resulting in unexpected behavior, lurching, or othernegative events that cause driver discomfort. In certain embodiments,differential speed values between shafts in a transmission can causeoscillation upon decoupling from the prime mover, and/or a torquetransient in the prime mover can cause oscillation in transmissioncomponents while still coupled to the transmission. In certainembodiments, the clutch control circuit 19812 modulates the clutchcommand 19902 to provide a selected clutch slip amount to prevent ormitigate the transient response of the transmission components. Incertain embodiments, the clutch slip amount is provided in response tothe strength of the expected transient, and/or provided to allow smoothtransition of transmission components between the starting state and theending state after the transition.

Referencing FIG. 89, an example controller 17110 includes a vehicleenvironment circuit 8902 that performs an operation a) to interpret amotive torque value 8908, a vehicle grade value 8910, and a vehicleacceleration value 8912. The example controller 17110 further includes amass estimation circuit 8904 that performs an operation b) to determinea first correlation (e.g., one of correlations 8920) such as a firstcorrelation 8920 between the motive torque value 8908 and the vehiclegrade value 8910. Example and non-limiting operations to determine acorrelation 8920 include determining whether the estimated values movetogether (e.g. increase or decrease together), the consistency of anysuch movement, the rate of change of any such movement, and/or thecharacter of such movement (e.g. whether the correlated movement islinear). The example mass estimation circuit 8904 further determines asecond correlation (e.g., one of correlations 8920) between the motivetorque value 8908 and the vehicle acceleration value 8912, and a thirdcorrelation (e.g., one of correlations 8920) between the vehicle gradevalue and the vehicle acceleration value. The example mass estimationcircuit 8904 further performs an operation c) to adapt an estimatedvehicle mass value 8914, an estimated vehicle drag value 8916, and anestimated vehicle effective inertia value 8918 in response to the firstcorrelation 8920, the second correlation 8920, and the third correlation8920.

The example controller 17110 further includes a model consistencycircuit 8906 that performs an operation d) to determine an adaptationconsistency value 8924, and in response to the adaptation consistencyvalue 8924, to adjust an adaptation rate 8922 of the adapting. Thevehicle environment circuit 8902, the mass estimation circuit 8904, andthe model consistency circuits 8906 further iteratively performoperations a), b), c), and d) to provide an updated estimated vehiclemass value 8926. In certain embodiments, a launch characterizationcircuit 18902 (e.g., see the disclosure referencing FIG. 77) interpretsthe updated estimated vehicle mass value 8926 as one of the at least onelaunch parameters 18904.

An example model consistency circuit 8906 further performs the operationc) to slow or halt an adapting the estimated values in response to thefirst correlation 8920, the second correlation 8920, and/or the thirdcorrelation 8920 having an unexpected correlation configuration (e.g.,correlation configuration does not match the expected correlationconfiguration 8928), and/or increases the adapting rate 8922 orcontinues the adapting the estimated values 8914, 8916, 8918 in responseto the first correlation 8920, the second correlation 8920, and/or thethird correlation 8920 having an expected correlation configuration8928. An example expected correlation configuration 8928 includes acorrelation such as: a positive correlation for the first correlation8920 and the second correlation 8920 (e.g., one or both of the firstcorrelation and the second correlation 8920 indicate the correlatedparameters increase or decrease together), and a negative correlationfor the third correlation 8920 (e.g., the correlated parameters move inopposing directions). Additionally or alternatively, an expectedcorrelation configuration 8928 includes a linearity value correspondingto one or more of the first correlation 8920, the second correlation8920, and the third correlation 8920. An example unexpected correlationconfiguration includes at least one correlation such as: a negativecorrelation for the first correlation 8920 or the second correlation8920; a positive correlation for the third correlation 8920; and/or anon-linear correlation corresponding to any one or more of the firstcorrelation 8920, the second correlation 8920, and the third correlation8920. An example model consistency circuit 8906 further performs theoperation c) to adjust the adaptation rate 8922 by increasing or holdingan adjustment step size (e.g., as the adaptation rate 8922) in at leastone of the estimated vehicle mass value 8914, the estimated vehicleeffective inertia value 8918, or the estimated vehicle drag value 8916in response to: an adaptation result such as monotonically changing eachestimated value 8914, 8916, 8918; and/or monotonically changing at leastone of the estimated values 8914, 8916, 8918 and holding the otherestimated values at a same value 8914, 8916, 8918. An example modelconsistency circuit 8906 further performs the operation c) to adjust theadaptation rate 8922 by: decreasing an adjustment step size in at leastone of the estimated vehicle mass value 8914, the estimated vehicleeffective inertia value 8918, or the estimated vehicle drag value 8916in response to: changing a direction of adaptation in at least one ofthe estimated values 8914, 8916, 8918. A determination that an estimateis being held at a same value includes, in certain embodiments, adetermination that a value has changed below a threshold amount (e.g.vehicle mass estimate 8914 decreasing by a small amount may beinterpreted as no change), and/or a determination that a value ischanging at a rate that is lower than a threshold (e.g. vehicle massestimate 8914 increasing lower than a given amount per unit time, perexecution cycle, and/or per trip may be interpreted as no change). Incertain embodiments, estimates 8914, 8916, 8918 may be subjected tofiltering, debouncing (e.g. ignoring and/or limiting outlying or highchange rate determinations), hysteresis (e.g., determining that adirection change in the estimate has not occurred at a varying thresholdwhen changing directions, and/or at a different threshold for increasingversus decreasing).

Referencing FIG. 90, an example controller 17110 includes a frictionbrake control circuit 18406 that provides a friction brake engagementcommand 9002. In certain embodiments, a transmission 100 includes afriction brake responsive to the friction brake engagement command 9002to engage a countershaft. An example friction brake control circuit18406 further tracks an engaged time 9006 of the friction brake anddetermines a target release time 9004 for the friction brake, determinesa release delay 9008 for the friction brake in response to the engagedtime 9006, and commands (e g utilizing friction brake engagement command9002) a release of the friction brake in response to the release delay9008 and the target release time 9004. An example friction brake controlcircuit 18406 further determines the target release time 9004 and/or therelease delay 9008 in response to a transmission temperature value 9010.For example, the longer the friction brake is engaged, in certainconfigurations, the greater the time it takes for the friction brake todisengage after an actuator releases the friction brake—for example dueto a greater pressure in a friction brake actuating volume 9012 and/ordue to other system dynamics. In certain embodiments, the temperatureaffects the pressure decay and other system dynamics, and utilization ofa temperature compensation can improve the accuracy of the frictionbrake disengagement, resulting in improved correspondence betweenplanned and actual friction brake control of countershaft speed. Anytemperature in a system can be utilized to compensate the friction brakecontrol, although temperatures more closely related to the frictionbrake components and/or friction brake actuating volume 9012 provide, incertain embodiments, improved accuracy and precision of thecompensation. Accordingly, the transmission temperature value 9010includes, without limitation, a transmission oil temperature, atransmission coolant temperature (where present), an ambienttemperature, an actuator temperature, and/or any temperature such asfrom a sensor positioned in proximity to the friction brake,countershaft, and/or friction brake actuating volume 9012.

An example friction brake control circuit 18406 further determines therelease delay 9008 by determining a pressure decay value 9014 in afriction brake actuating volume 9012. In certain embodiments, thefriction brake control circuit 18406 determines the pressure decay value9014 by determining a pressure in the friction brake actuating volume9012, which may be measured, modeled, and/or estimated. An examplefriction brake control circuit 18406 further determines the pressuredecay value 9014 by utilizing a pre-determined relationship 9020 betweenengaged time 9006 and pressure decay in the friction brake actuatingvolume 9012. An example friction brake control circuit 18406 determinesa speed differential 9018 between the countershaft and an engagingshaft, and determines the target release time 9004 further in responseto the speed differential 9018—for example to slow the countershaft ascheduled amount during a shift, diagnostic, or other operation. Exampleand non-limiting engaging shafts include an output shaft, a main shaft,and/or an input shaft.

Referencing FIG. 91, an example controller 17110 includes a shiftcontrol circuit 19808 that determines that a synchronizer engagement9102 is imminent, for example in accordance with a shift actuator railposition 9110, shift actuator rail velocity 9108, and/or in response toa timing of the shift actuator (e.g. a time after actuation iscommanded, and/or a timing after the shift actuator disengages from apreviously engaged gear). The example shift control circuit 19808provides a first opposing pulse command 9104 and/or a second opposingpulse command 9106 (e.g., where a first opposing pulse command 9104 waspreviously provided to control a shift rail actuator velocity 9108) inresponse to the imminent synchronizer engagement 9102. The exampleoperations of the shift control circuit 19808 provide for improved wearon the synchronizer, controlled engagement force of the synchronizer,reduced noise of shifts in a transmission 100, and/or provide forincreased velocity of the shift actuator during a shift whilecontrolling synchronization forces. An example shift control circuit19808 further provides the one of the first opposing pulse command 9104and/or a second opposing pulse command 9106 further in response to avelocity 9108 of the shift actuator and a target velocity 9114 of theshift actuator, for example to control the velocity 9108 to or towardthe target velocity 9114.

An example shift control circuit 19808 further provides a first opposingpulse command 9104 after the first actuating pulse command 9112, andfurther in response to an expiration of a predetermined opposing pulsedelay time 9116. In certain embodiments, a first opposing pulse command9104 is provided at a delay time 9116 after the first actuating pulsecommand 9112 is provided, and/or at a delay time 9116 afterdisengagement of the shift actuator occurs from a previously engagedgear. An example shift control circuit 19808 further interrupts thefirst opposing pulse command 9104 in response to a shift actuator railposition 9110, for example to provide a scheduled amount of oppositionto the shift actuator. In certain embodiments, the pulse timing (e.g.,the start of the pulse) of the first and/or second opposing pulsecommands 9104, 9106 are timed (e.g. after a shift request, an actuatingpulse command 9112, and/or disengagement), and the completion or pulsewidth of the opposing pulse commands 9104, 9106 are based on shiftactuator position 9110 and/or velocity 9108.

Referencing FIG. 92, an example controller 17110 includes a shiftcontrol circuit 19808 that provides a first opposing pulse (e.g. byproviding a first opposing pulse command 9104), the first opposing pulseincluding a first predetermined amount of air 9202 above an ambientamount of air in a first closed volume, where pressure in the firstclosed volume opposes movement of a shift actuator in a shift direction.The example shift control circuit 19808 a first actuating pulse (e.g. byproviding a first actuating pulse command 9112), the first actuatingpulse including a second predetermined amount of air 9204 above anambient amount of air in a second closed volume, where pressure in thesecond closed volume promotes movement of the shift actuator in theshift direction. The example shift control circuit 19808 furtherreleases pressure in the first closed volume and the second closedvolume in response to determining a shift completion event. The shiftcontrol circuit 19808 provides the first opposing pulse command 9104before, after, or simultaneously with the first actuating pulse command9112, depending upon the desired dynamic response of the shift actuator.In certain embodiments, the shift control circuit 19808 provides thesecond opposing pulse command 9106 in response to the shift actuatorapproaching a synchronization position (e.g. to control engagementvelocity and/or force) and/or provides an additional opposing pulsecommand (the second 9106 or a subsequent opposing pulse command) as theshift actuator engages (e.g., as the synchronizer comes off the block).The description including predetermined amounts of air includesdetermining the amounts of air in response to system conditions beforecommanding the pulses (e.g., shaft speeds, shift timing, temperatures inthe system, effects of wear on components, etc.) and/or may furthermodulate the pulse commands during the providing of the commands,including schedule modulation (e.g., a PWM to provide less than fullactuation pressure, and/or in response to feedback of shift actuatorposition 9110 and/or velocity 9108). The shift control circuit 19808provides, in certain embodiments, any number of opposing and/oractuating pulse commands. In certain embodiments, the shift controlcircuit 19808 releases pressure from the opposing and/or actuating sidesto coordinate pressure decay in the opposing and actuating sides—forexample to control forces that engage the gear and/or to avoiddisengaging the gear after the shift event is completed.

An example shift control circuit 19808 further modulates the firstactuating pulse command 9112 in response to a previously determined geardeparture position value 9206—for example and observed shift milposition value whereupon the shift actuator has disengaged from thecurrently engaged gear at the start of a shift. In certain embodiments,the modulating includes providing the first actuating pulse command 9112as a full open command (e.g., full actuation) in response to a position9110 of the shift actuator being on an engaged side of the geardeparture position value 9206, and additionally or alternativelyincludes providing the first actuating pulse command 9112 as apulse-width modulated (PWM) command and/or as a reduced actuationcommand in response to the position 9110 of the shift actuatorapproaching and/or exceeding the gear departure position value 9206. Thegear departure position value 9206 can vary due to part-to-partvariations and stackup, and additionally can change over time due towear and/or service events. Accordingly, in certain embodiments, theshift control circuit 19808 additionally observes actual gear departure(e.g., by observing shift rail position 9110 and/or velocity 9108), andupdates the gear departure position value 9206 in response to theobservation. The updating may be filtered, rate limited, debounced,and/or subjected to other rationalization techniques. In certainembodiments, where a large change is detected, the change may beimplemented more quickly, ignored, and/or changed quickly after severalobservations confirm the updated value. In certain embodiments, theshift control circuit 19808 performs a calibration test whereupon theshift actuator engages and disengages the gear multiple times todetermine the departure position. Such calibration operations may beperformed when vehicle operating conditions allow (e.g., another gearmesh in the system is enforcing a neutral position and/or the vehicle isnot moving) and/or in response to a specified command such as from aservice tool, as part of a service event, and/or at a time ofmanufacture or reconditioning.

An example shift control circuit 19808 further interprets asynchronization speed differential value 9210 for a currently requestedshift including a selected gear ratio (e.g., gear selection 9304). Theexample shift control circuit 19808, in response to the final gear meshengagement speed differential value 9210 (e.g., the speed differentialat an intended gear mesh engagement) exceeding a smooth engagementthreshold 9208, changes the currently requested shift to a changed gearratio (e.g., updating the gear selection 9304), where the changed gearratio includes a second synchronization speed differential value 9210lower than the smooth engagement threshold 9208. For example, during ashift, operating conditions may change the predicted speed of shafts inthe transmission 100 (e.g., a vehicle acceleration or decelerationduring the shift, a change in a shaft speed from friction brakeengagement, etc.), such that an originally intended gear selection 9304has a higher speed differential than planned. In certain embodiments,the shift control circuit 19808 updates the gear selection 9304 beforethe shift commences (e.g., operator and/or nominal controls select agear that is not predicted to result in a smooth shift based on thecurrent operating conditions), and/or after the shift actuator hasdisengaged a prior engaged gear (e.g., a mid-shift gear selection 9304change).

Referencing FIG. 93 an example controller 17110 includes a neutralsensing circuit 9302 structured to determine a shift rail positionsensor failure 9306 indicating that a shift rail position sensorcorresponding to a shift actuator controlling a reverse gear is failed,and that a gear selection 9304 is active requiring operations of theshift actuator. The example controller 17110 further includes a neutralenforcement circuit 18204 that, in response to the gear selection 9304and the shift rail position sensor failure 9306, performs in order:commanding the shift actuator to a neutral position, confirming theneutral position by commanding a second shift actuator to engage asecond gear, where the second shift actuator is not capable of engagingthe second gear unless the shift actuator is in the neutral position,and confirming the second shift actuator has engaged the second gear.The example controller 17110 further includes a shift control circuit19808 to command the command the shift actuator into the gear positionin response to the gear selection 9304 after the neutral position isconfirmed.

Referencing FIG. 94, an example controller 17110 includes a backlashindication circuit 18002 that identifies an imminent backlash crossingevent 18006 at a first gear mesh, and a backlash management circuit 9402that reduces engagement force experienced by the first gear mesh inresponse to receiving a backlash crossing indication event 18006 fromthe backlash indication circuit 18002. The example controller 17110further includes a shaft displacement circuit 9602 that interprets ashaft displacement angle 9604, the shaft displacement angle 9604including an angle value representative of a rotational displacementdifference between at least two shafts of a transmission. The examplecontroller 17110 further includes a zero torque determination circuit9806 that determines the transmission is operating in a zero torqueregion 9808 in response to the shaft displacement angle 9604 including adifference value below a zero torque threshold value 9814, and where thebacklash indication circuit 18002 further identifies the imminentbacklash crossing event 18006 in response to the transmission operatingin the zero torque region 9808. Example operations of the backlashindication circuit 18002 to identify the imminent backlash crossingevent 18006 include operations such as: determining that an imminentrotational direction of the first gear mesh in a transmission is anopposite rotational direction to an established rotational direction ofthe first gear mesh; determining that a speed change between a firstshaft comprising gears on one side of the first gear mesh and a secondshaft comprising gears on an opposing side of the first gear mesh islikely to induce the backlash crossing event; determining that a gearshift occurring at a second gear mesh is likely to induce the backlashcrossing event at the first gear mesh; determining that a transmissioninput torque value indicates an imminent zero crossing event; and/ordetermining that a vehicle operating condition is likely to induce thebacklash crossing event. An example backlash management circuit 9402further manages backlash by performing an operation such as disengagingthe first gear mesh during at least a portion of the backlash crossingevent; disengaging a clutch during at least a portion of the backlashcrossing event; and/or slipping a clutch during at least a portion ofthe backlash crossing event. An example backlash indication circuit18002 identifies the imminent backlash crossing event 18006 bydetermining that a gear shift occurring at a second gear mesh is likelyto induce the backlash crossing event 18006 at the first gear mesh,where the backlash management circuit 9402 further performs adisengagement of the first gear mesh during at least of portion of thegear shift.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear and at least one set of drive gearshaving teeth with substantially flat tops to improve at least one ofnoise and efficiency. In embodiments, an automated truck transmission isprovided, using a plurality of high speed countershafts that areconfigured to be mechanically coupled to the main drive shaft by aplurality of gears when the transmission is in gear and an integratedmechanical assembly with a common air supply for both shift actuationand clutch actuation for the transmission.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear and a having at least one helical gearset to reduce noise.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear, where the gears have teeth that areconfigured to engage with a sliding velocity of engagement that provideshigh efficiency.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear and having enclosure bearings and gearsets configured to reduce noise from the transmission.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear and having a mechanically andelectrically integrated assembly configured to be mounted on thetransmission, wherein the assembly provides gear shift actuation andclutch actuation.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear and having wormwheel-ground gear teethhaving a tooth profile that is designed to provide efficient interactionof the gears.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear and having three gear systems havingthree, three and two modes of engagement respectively for providing an18 speed transmission.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear and having a three-by-three-by-two gearset architecture.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear; low contact ratio gears; bearings toreduce the impact of thrust loads on efficiency; and a low losslubrication system.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear and having an integrated assembly thatincludes a linear clutch actuator, at least one position sensor, andvalve banks for gear shift and clutch actuation.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear and having a pneumatic, linear clutchactuation system that is configured to hold substantially no volume ofunused air.

In embodiments, an automated truck transmission is provided, using aplurality of high speed countershafts that are configured to bemechanically coupled to the main drive shaft by a plurality of gearswhen the transmission is in gear and having at least one power take-off(PTO) interface that has an aluminum enclosure and a gear set that isoptimized for a specified use of the PTO.

In embodiments, an automated truck transmission may have variousenclosures, such as for separating various gear boxes, such as in a3×2×2 gear box architecture. The enclosures may have bearings, and inembodiments, the enclosure bearings may be configured to be isolatedfrom the thrust loads of the transmission. For example, in embodimentsan automatic truck transmission architecture is provided where one ormore of the enclosure bearings take radial separating loads, and thethrust reaction loads are substantially deployed on other bearings (notthe enclosure bearings).

In embodiments, an automatic truck transmission architecture is providedwherein enclosure bearings take radial separating loads, wherein thrustreaction loads are deployed on other bearings and a common air supplythat is used for gear shift actuation and for clutch actuation for thetransmission.

In embodiments, an automatic truck transmission architecture is providedwherein enclosure bearings take radial separating loads, wherein thrustreaction loads are deployed on other bearings and wherein the automatedtruck transmission has at least one set of drive gears having teeth withsubstantially flat tops to improve at least one of noise and efficiency.

In embodiments, an automatic truck transmission architecture is providedwherein enclosure bearings take radial separating loads, wherein thrustreaction loads are deployed on other bearings and wherein a helical gearset is provided to reduce noise.

In embodiments, an automatic truck transmission architecture is providedwherein enclosure bearings take radial separating loads, wherein thrustreaction loads are deployed on other bearings and wherein thetransmission has wormwheel-ground gear teeth having a tooth profile thatis designed to provide efficient interaction of the gears.

In embodiments, an automatic truck transmission architecture is providedwherein enclosure bearings take radial separating loads, wherein thrustreaction loads are deployed on other bearings and wherein thetransmission has three gear systems having three, three and two modes ofengagement respectively for providing an 18 speed transmission.

In embodiments, an automatic truck transmission architecture is providedwherein enclosure bearings take radial separating loads, wherein thrustreaction loads are deployed on other bearings and wherein thetransmission has a three-by-three-by-two gear set architecture.

In embodiments, an automatic truck transmission architecture is providedhaving enclosure bearings that take radial separating loads, havingthrust reaction loads that are deployed on other bearings and having apneumatic, linear clutch actuation system that is configured to holdsubstantially no volume of unused air.

In embodiments, an automatic truck transmission architecture is providedhaving enclosure bearings that take radial separating loads, havingthrust reaction loads that are deployed on other bearings and having aplurality of power take-off (PTO) interfaces.

In embodiments, an automated truck transmission is provided, having atleast one set of drive gears that has teeth with substantially flat topsto improve at least one of noise and efficiency and having an integratedmechanical assembly with a common air supply for both shift actuationand clutch actuation for the transmission.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency and wherein a helical gearset is provided to reduce noise.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat topsconfigured to engage with a sliding velocity of engagement that provideshigh efficiency.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency and wherein enclosurebearings and gear sets are configured to reduce noise from thetransmission.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency and wherein thetransmission has a mechanically and electrically integrated assemblyconfigured to be mounted on the transmission, wherein the assemblyprovides gear shift actuation and clutch actuation.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency and wormwheel-ground gearteeth having a tooth profile that is designed to provide efficientinteraction of the gears.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency and wherein thetransmission has three gear systems having three, three and two modes ofengagement respectively for providing an 18 speed transmission.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency of at least one gear set ina three-by-three-by-two gear set architecture.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency and wherein thetransmission has low contact ratio gears, bearings to reduce the impactof thrust loads on efficiency and a low loss lubrication system.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency and wherein thetransmission has a linear clutch actuator that is integrated with theshift actuation system for the transmission.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency and wherein thetransmission has a hoseless pneumatic actuation system for at least oneof clutch actuation and gear shift actuation.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency and wherein thetransmission has a centralized actuation system wherein the sameassembly provides clutch actuation and gear shift actuation.

In embodiments, an automated truck transmission is provided, wherein atleast one set of drive gears has teeth with substantially flat tops toimprove at least one of noise and efficiency and wherein thetransmission has a pneumatic, linear clutch actuation system that isconfigured to hold substantially no volume of unused air.

In embodiments, an automated truck transmission is provided having anintegrated mechanical assembly with a common air supply that is used forboth gear shift actuation and clutch actuation and three gear systemshaving three, three and two modes of engagement respectively forproviding an 18 speed transmission.

In embodiments, an automated truck transmission is provided having anintegrated mechanical assembly with a common air supply that is used forboth gear shift actuation and clutch actuation and having athree-by-three-by-two gear set architecture.

In embodiments, an automated truck transmission is provided having anintegrated mechanical assembly with a common air supply that is used forboth gear shift actuation and clutch actuation and having low contactratio gears, bearings to reduce the impact of thrust loads on efficiencyand a low loss lubrication system.

Various embodiments disclosed herein may include an aluminum automatedtruck transmission, wherein a helical gear is used for at least one gearset of the transmission to reduce noise from the transmission. A helicalgear set may be used in combination with various other methods, systemsand components of an automated truck transmission disclosed throughoutthis disclosure, including the following.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having a set ofsubstantially circular gears with teeth that are configured to engagewith a sliding velocity of engagement that provides high efficiency.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having enclosurebearings and gear sets configured to reduce noise from the transmission.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having amechanically and electrically integrated assembly configured to bemounted on the transmission, wherein the assembly provides gear shiftactuation and clutch actuation.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and havingwormwheel-ground gear teeth having a tooth profile that is designed toprovide efficient interaction of the gears.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having three gearsystems having three, three and two modes of engagement respectively forproviding an 18 speed transmission.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having athree-by-three-by-two gear set architecture.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having lowcontact ratio gears, bearings to reduce the impact of thrust loads onefficiency and a low loss lubrication system.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having a linearclutch actuator that is integrated with the shift actuation system forthe transmission.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having anintegrated assembly that includes a linear clutch actuator, at least oneposition sensor, and valve banks for gear shift and clutch actuation.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having a hoselesspneumatic actuation system for at least one of clutch actuation and gearshift actuation.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having a gearsystem configured to have bearings accept thrust loads to improve engineefficiency.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having acentralized actuation system wherein the same assembly provides clutchactuation and gear shift actuation.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having apneumatic, linear clutch actuation system that is configured to holdsubstantially no volume of unused air.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having aplurality of power take-off (PTO) interfaces.

In embodiments, an aluminum automated truck transmission is provided,having a helical gear as set as at least one gear set of thetransmission to reduce noise from the transmission and having at leastone power take-off (PTO) interface that has an aluminum enclosure and agear set that is optimized for a specified use of the PTO.

In embodiments, an automated truck transmission is provided, wherein thegear set comprises a plurality of substantially circular gears havingteeth that are configured to engaged during at least one operating modeof the automated truck transmission, configuring the shape of the teethof the gears based on the sliding velocity of engagement of the teethtop provide improved efficiency of the automated truck transmission.Embodiments with gear teeth optimized based on sliding velocity may beused in combination with various other methods, systems and componentsof an overall architecture for an efficient, low noise transmission,including as follows.

Embodiments of the present disclosure include ones for a die castaluminum automatic truck transmission is provided, wherein the enclosurebearings and gear sets are configured to reduce noise from thetransmission. Such a noise-reduced configuration can be used incombination with other methods, systems and components of an automatictruck transmission architecture as described throughout the presentdisclosure.

In embodiments, a die cast aluminum automatic truck transmission isprovided, having enclosure bearings and gear sets configured to reducenoise from the transmission and having low contact ratio gears, bearingsto reduce the impact of thrust loads on efficiency and a low losslubrication system.

In embodiments, a die cast aluminum automatic truck transmission isprovided, having enclosure bearings and gear sets configured to reducenoise from the transmission and having a linear clutch actuator that isintegrated with the shift actuation system for the transmission.

In embodiments, a die cast aluminum automatic truck transmission isprovided, having enclosure bearings and gear sets configured to reducenoise from the transmission and having an integrated assembly thatincludes a linear clutch actuator, at least one position sensor, andvalve banks for gear shift and clutch actuation.

In embodiments, a die cast aluminum automatic truck transmission isprovided, having enclosure bearings and gear sets configured to reducenoise from the transmission and having a gear system configured to havebearings accept thrust loads to improve engine efficiency.

In embodiments, a die cast aluminum automatic truck transmission isprovided, having enclosure bearings and gear sets configured to reducenoise from the transmission and having a centralized actuation systemwherein the same assembly provides clutch actuation and gear shiftactuation.

In embodiments, an automated truck transmission is provided, wherein thebearings for the gears are configured to reduce or cancel thrust loadswhen the drive shaft is engaged. Such an architecture may be used incombination with various other methods, systems and components describedthroughout this disclosure, including as follows.

In embodiments, an automated truck transmission is provided having agear system configured to having bearings accept thrust loads to improveengine efficiency and having a centralized actuation system wherein thesame assembly provides clutch actuation and gear shift actuation.

In embodiments, an automated truck transmission is provided having agear system configured to having bearings accept thrust loads to improveengine efficiency and having a pneumatic, linear clutch actuation systemthat is configured to hold substantially no volume of unused air.

In embodiments, an automated truck transmission is provided having agear system configured to having bearings accept thrust loads to improveengine efficiency and having a plurality of power take-off (PTO)interfaces.

In embodiments, an automated truck transmission is provided having agear system configured to having bearings accept thrust loads to improveengine efficiency and having at least one power take-off (PTO) interfacethat has an aluminum enclosure and a gear set that is optimized for aspecified use of the PTO.

In embodiments, an automated truck transmission is provided, wherein thetransmission has a plurality of power take-off (PTO) interfaces. Such anarchitecture may be used in combination with various other methods,systems and components described throughout this disclosure, includingas follows. In embodiments, an automated truck transmission is providedhaving a plurality of power take-off (PTO) interfaces and having atleast one power take-off (PTO) interface that has an aluminum enclosureand a gear set that is optimized for a specified use of the PTO.

In embodiments, an automated truck transmission is provided, wherein thetransmission has at least one power take-off (PTO) interface with analuminum enclosure and an optimized gear set. Such an architecture maybe used in combination with various other methods, systems andcomponents described throughout this disclosure.

While only a few embodiments of the present disclosure have been shownand described, it will be obvious to those skilled in the art that manychanges and modifications may be made thereunto without departing fromthe spirit and scope of the present disclosure as described in thefollowing claims. All patent applications and patents, both foreign anddomestic, and all other publications referenced herein are incorporatedherein in their entireties to the full extent permitted by law.

Any one or more of the terms computer, computing device, processor,circuit, and/or server include a computer of any type, capable to accessinstructions stored in communication thereto such as upon anon-transient computer readable medium, whereupon the computer performsoperations of systems or methods described herein upon executing theinstructions. In certain embodiments, such instructions themselvescomprise a computer, computing device, processor, circuit, and/orserver. Additionally or alternatively, a computer, computing device,processor, circuit, and/or server may be a separate hardware device, oneor more computing resources distributed across hardware devices, and/ormay include such aspects as logical circuits, embedded circuits,sensors, actuators, input and/or output devices, network and/orcommunication resources, memory resources of any type, processingresources of any type, and/or hardware devices configured to beresponsive to determined conditions to functionally execute one or moreoperations of systems and methods herein.

The methods and systems described herein may be deployed in part or inwhole through network infrastructures. The network infrastructure mayinclude elements such as computing devices, servers, routers, hubs,firewalls, clients, personal computers, communication devices, routingdevices and other active and passive devices, modules, and/or componentsas known in the art. The computing and/or non-computing device(s)associated with the network infrastructure may include, apart from othercomponents, a storage medium such as flash memory, buffer, stack, RAM,ROM and the like. The methods, program code, instructions, and/orprograms described herein and elsewhere may be executed by one or moreof the network infrastructural elements.

The methods, program code, instructions, and/or programs may be storedand/or accessed on machine readable transitory and/or non-transitorymedia that may include: computer components, devices, and recordingmedia that retain digital data used for computing for some interval oftime; semiconductor storage known as random access memory (RAM); massstorage typically for more permanent storage, such as optical discs,forms of magnetic storage like hard disks, tapes, drums, cards and othertypes; processor registers, cache memory, volatile memory, non-volatilememory; optical storage such as CD, DVD; removable media such as flashmemory (e.g., USB sticks or keys), floppy disks, magnetic tape, papertape, punch cards, standalone RAM disks, Zip drives, removable massstorage, off-line, and the like; other computer memory such as dynamicmemory, static memory, read/write storage, mutable storage, read only,random access, sequential access, location addressable, fileaddressable, content addressable, network attached storage, storage areanetwork, bar codes, magnetic ink, and the like.

Certain operations described herein include interpreting, receiving,and/or determining one or more values, parameters, inputs, data, orother information. Operations including interpreting, receiving, and/ordetermining any value parameter, input, data, and/or other informationinclude, without limitation: receiving data via a user input; receivingdata over a network of any type; reading a data value from a memorylocation in communication with the receiving device; utilizing a defaultvalue as a received data value; estimating, calculating, or deriving adata value based on other information available to the receiving device;and/or updating any of these in response to a later received data value.In certain embodiments, a data value may be received by a firstoperation, and later updated by a second operation, as part of thereceiving a data value. For example, when communications are down,intermittent, or interrupted, a first operation to interpret, receive,and/or determine a data value may be performed, and when communicationsare restored an updated operation to interpret, receive, and/ordetermine the data value may be performed.

Certain logical groupings of operations herein, for example methods orprocedures of the current disclosure, are provided to illustrate aspectsof the present disclosure. Operations described herein are schematicallydescribed and/or depicted, and operations may be combined, divided,re-ordered, added, or removed in a manner consistent with the disclosureherein. It is understood that the context of an operational descriptionmay require an ordering for one or more operations, and/or an order forone or more operations may be explicitly disclosed, but the order ofoperations should be understood broadly, where any equivalent groupingof operations to provide an equivalent outcome of operations isspecifically contemplated herein. For example, if a value is used in oneoperational step, the determining of the value may be required beforethat operational step in certain contexts (e.g. where the time delay ofdata for an operation to achieve a certain effect is important), but maynot be required before that operation step in other contexts (e.g. whereusage of the value from a previous execution cycle of the operationswould be sufficient for those purposes). Accordingly, in certainembodiments an order of operations and grouping of operations asdescribed is explicitly contemplated herein, and in certain embodimentsre-ordering, subdivision, and/or different grouping of operations isexplicitly contemplated herein.

The methods and systems described herein may transform physical and/oror intangible items from one state to another. The methods and systemsdescribed herein may also transform data representing physical and/orintangible items from one state to another.

The elements described and depicted herein, including in flow charts,block diagrams, and/or operational descriptions, depict and/or describespecific example arrangements of elements for purposes of illustration.However, the depicted and/or described elements, the functions thereof,and/or arrangements of these, may be implemented on machines, such asthrough computer executable transitory and/or non-transitory mediahaving a processor capable of executing program instructions storedthereon, and/or as logical circuits or hardware arrangements.Furthermore, the elements described and/or depicted herein, and/or anyother logical components, may be implemented on a machine capable ofexecuting program instructions. Thus, while the foregoing flow charts,block diagrams, and/or operational descriptions set forth functionalaspects of the disclosed systems, any arrangement of programinstructions implementing these functional aspects are contemplatedherein. Similarly, it will be appreciated that the various stepsidentified and described above may be varied, and that the order ofsteps may be adapted to particular applications of the techniquesdisclosed herein. Additionally, any steps or operations may be dividedand/or combined in any manner providing similar functionality to thedescribed operations. All such variations and modifications arecontemplated in the present disclosure. The methods and/or processesdescribed above, and steps thereof, may be implemented in hardware,program code, instructions, and/or programs or any combination ofhardware and methods, program code, instructions, and/or programssuitable for a particular application. Example hardware includes adedicated computing device or specific computing device, a particularaspect or component of a specific computing device, and/or anarrangement of hardware components and/or logical circuits to performone or more of the operations of a method and/or system. The processesmay be implemented in one or more microprocessors, microcontrollers,embedded microcontrollers, programmable digital signal processors orother programmable device, along with internal and/or external memory.The processes may also, or instead, be embodied in an applicationspecific integrated circuit, a programmable gate array, programmablearray logic, or any other device or combination of devices that may beconfigured to process electronic signals. It will further be appreciatedthat one or more of the processes may be realized as a computerexecutable code capable of being executed on a machine readable medium.

The computer executable code may be created using a structuredprogramming language such as C, an object oriented programming languagesuch as C++, or any other high-level or low-level programming language(including assembly languages, hardware description languages, anddatabase programming languages and technologies) that may be stored,compiled or interpreted to run on one of the above devices, as well asheterogeneous combinations of processors, processor architectures, orcombinations of different hardware and computer readable instructions,or any other machine capable of executing program instructions.

Thus, in one aspect, each method described above and combinationsthereof may be embodied in computer executable code that, when executingon one or more computing devices, performs the steps thereof. In anotheraspect, the methods may be embodied in systems that perform the stepsthereof, and may be distributed across devices in a number of ways, orall of the functionality may be integrated into a dedicated, standalonedevice or other hardware. In another aspect, the means for performingthe steps associated with the processes described above may include anyof the hardware and/or computer readable instructions described above.All such permutations and combinations are contemplated in embodimentsof the present disclosure.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the disclosure (especially in the context of thefollowing claims) is to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. All methods described hereincan be performed in any suitable order unless otherwise indicated hereinor otherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate the disclosure and does not pose alimitation on the scope of the disclosure unless otherwise claimed. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential to the practice of the disclosure.

It will be appreciated that the methods and systems described are setforth by way of example and not of limitation. Numerous variations,additions, omissions, and other modifications will be apparent to one ofordinary skill in the art. In addition, the order or presentation ofmethod steps in the description and drawings above is not intended torequire this order of performing the recited steps unless a particularorder is expressly required or otherwise clear from the context. Thus,while particular embodiments have been shown and described, it will beapparent to those skilled in the art that various changes andmodifications in form and details may be made therein without departingfrom the spirit and scope of this disclosure and are intended to form apart of the invention as defined by the following claims, which are tobe interpreted in the broadest sense allowable by law.

What is claimed is:
 1. A transmission, comprising: an input shaftconfigured to couple to a prime mover; a countershaft having a firstplurality of gears mounted thereon; a main shaft having a secondplurality of gears mounted thereon; an output shaft selectivelyproviding a torque output to a driveline; a shift actuator structured toselectively couple the input shaft to the main shaft by rotatablycoupling at least one of the first plurality of gears to thecountershaft and the second plurality of gears to the main shaft,wherein the shift actuator is mounted on an exterior wall of a housing,and wherein the countershaft and the main shaft are at least partiallypositioned within the housing; a controller comprising a shiftcharacterization circuit structured to determine that a transmissionshift operation is experiencing a tooth butt event; wherein thetransmission further comprises a means for clearing the tooth buttevent; wherein the means for clearing the tooth butt event furthercomprises the controller further comprising a clutch control circuit isfurther structured to command a clutch slip event in response to thetooth butt event.
 2. A transmission, comprising: an input shaftconfigured to couple to a prime mover; a countershaft having a firstplurality of gears mounted thereon; a main shaft having a secondplurality of gears mounted thereon; an output shaft selectivelyproviding a torque output to a driveline; a shift actuator structured toselectively couple the input shaft to the main shaft by rotatablycoupling at least one of the first plurality of gears to thecountershaft and the second plurality of gears to the main shaft,wherein the shift actuator is mounted on an exterior wall of a housing,and wherein the countershaft and the main shaft are at least partiallypositioned within the housing; a controller comprising a shiftcharacterization circuit structured to determine that a transmissionshift operation is experiencing a tooth butt event; wherein thetransmission further comprises a means for clearing the tooth buttevent; wherein the means for clearing the tooth butt event comprises thecontroller further comprising a friction brake control circuitstructured to modulate a countershaft speed in response to the toothbutt event.
 3. A transmission, comprising: an input shaft configured tocouple to a prime mover; a countershaft having a first plurality ofgears mounted thereon; a main shaft having a second plurality of gearsmounted thereon; an output shaft selectively providing a torque outputto a driveline; a shift actuator structured to selectively couple theinput shaft to the main shaft by rotatably coupling at least one of thefirst plurality of gears to the countershaft and the second plurality ofgears to the main shaft, wherein the shift actuator is mounted on anexterior wall of a housing, and wherein the countershaft and the mainshaft are at least partially positioned within the housing; a controllercomprising a shift characterization circuit structured to determine thata transmission shift operation is experiencing a tooth butt event;wherein the transmission further comprises a means for clearing thetooth butt event; wherein the controller further comprises a shiftcontrol circuit structured to: provide a first opposing pulse command,the first opposing pulse command comprising a first predetermined amountof air above an ambient amount of air in a first closed volume, whereinpressure in the first closed volume opposes movement of the shiftactuator in a shift direction; determine a second predetermined amountof air in response to at least one of a speed of at least one of theshafts, an air supply pressure, and a transmission temperature value,the second predetermined amount of air comprising an amount of air abovean ambient amount of air in a second closed volume, wherein pressure inthe second closed volume promotes movement of the shift actuator in theshift direction; provide a first actuating pulse command, the firstactuating pulse command comprising the second predetermined amount ofair; and release pressure in the first closed volume and the secondclosed volume in response to determining a shift completion event; andwherein the shift actuator is responsive to the first opposing pulsecommand and the first actuating pulse command.
 4. A transmission,comprising: an input shaft configured to couple to a prime mover; acountershaft having a first plurality of gears mounted thereon; a mainshaft having a second plurality of gears mounted thereon; an outputshaft selectively providing a torque output to a driveline; a shiftactuator structured to selectively couple the input shaft to the mainshaft by rotatably coupling at least one of the first plurality of gearsto the countershaft and the second plurality of gears to the main shaft,wherein the shift actuator is mounted on an exterior wall of a housing,and wherein the countershaft and the main shaft are at least partiallypositioned within the housing; a controller comprising a shiftcharacterization circuit structured to determine that a transmissionshift operation is experiencing a tooth butt event; wherein thetransmission further comprises a means for clearing the tooth buttevent; a clutch structured to selectively decouple the prime mover fromthe input shaft; a progressive actuator operationally coupled to theclutch, wherein a position of the progressive actuator corresponds to aposition of the clutch; wherein the controller further comprises: aclutch characterization circuit structured to interpret a clutch torqueprofile, the clutch torque profile providing a relation between aposition of the clutch and a clutch torque value; a clutch controlcircuit structured to command a position of the progressive actuator inresponse to a clutch torque reference value and the clutch torqueprofile; and the clutch characterization circuit further structured tointerpret a position of the progressive actuator and an indicated clutchtorque, and to update the clutch torque profile in response to theposition of the progressive actuator and the indicated clutch torque. 5.The transmission of claim 4, wherein the clutch torque profile comprisesa first clutch engagement position value, and wherein the clutch controlcircuit is further structured to utilize the first clutch engagementposition value as a maximum zero torque position.
 6. The transmission ofclaim 4, further comprising: wherein the clutch torque profile comprisesa first clutch engagement position value and a second clutch engagementposition value, and wherein the clutch control circuit is furtherstructured to utilize the first clutch engagement position value as amaximum zero torque position and to utilize the second clutch engagementposition value as a minimum significant engagement torque position;wherein the clutch torque profile further comprises a clutch torquecurve comprising a plurality of clutch position values corresponding toa plurality of clutch torque values, wherein each of the clutch positionvalues is greater than the second clutch engagement position value; andwherein the clutch characterization circuit is further structured to:interpret the clutch torque profile by performing a clutch secondengagement position test, the clutch second engagement position testcomprising: determining that an input shaft speed is zero, the clutchcontrol circuit positioning the clutch at the second clutch engagementposition value, and comparing an acceleration of the input shaft speedto a second expected acceleration value of the input shaft speed; and toadjust the clutch torque curve in response to a change in the secondclutch engagement position value; and to determine that the clutch isoperating in a wear-through mode in response to at least one of thefirst clutch engagement position value and the second clutch engagementposition value changing at a rate greater than a clutch wear-throughrate value.
 7. The transmission of claim 6, wherein the controllerfurther comprises a friction brake control circuit, wherein thetransmission further comprises a friction brake selectively engaged tothe countershaft, and wherein the clutch second engagement position testfurther comprises the friction brake control circuit structured tocommand the friction brake to bring the input shaft speed to zero. 8.The transmission of claim 7, wherein the clutch characterization circuitis further structured to adjust the clutch torque curve in response to achange in the second clutch engagement position value.
 9. Atransmission, comprising: an input shaft configured to couple to a primemover; twin countershafts having a first plurality of gears mountedthereon; a main shaft having a second plurality of gears mountedthereon; an output shaft selectively providing a torque output to adriveline; a shift actuator structured to selectively couple the inputshaft to the main shaft by rotatably coupling at least one of the firstplurality of gears to the twin countershafts and the second plurality ofgears to the main shaft, wherein the shift actuator is mounted on anexterior wall of a housing, and wherein the twin countershafts and themain shaft are at least partially positioned within the housing; aclutch actuator housing, wherein a clutch actuator is positioned atleast partially within the clutch actuator housing; a controllercomprising a shift characterization circuit structured to determine thata transmission shift operation is experiencing a tooth butt event;wherein the transmission further comprises a means for clearing thetooth butt event and wherein the means for clearing the tooth butt eventfurther comprises the controller further comprising a clutch controlcircuit is further structured to command a clutch slip event in responseto the tooth butt event.
 10. A transmission, comprising: an input shaftconfigured to couple to a prime mover; twin countershafts having a firstplurality of gears mounted thereon; a main shaft having a secondplurality of gears mounted thereon; an output shaft selectivelyproviding a torque output to a driveline; a shift actuator structured toselectively couple the input shaft to the main shaft by rotatablycoupling at least one of the first plurality of gears to the twincountershafts and the second plurality of gears to the main shaft,wherein the shift actuator is mounted on an exterior wall of a housing,and wherein the twin countershafts and the main shaft are at leastpartially positioned within the housing; a clutch actuator housing,wherein a clutch actuator is positioned at least partially within theclutch actuator housing; a controller comprising a shiftcharacterization circuit structured to determine that a transmissionshift operation is experiencing a tooth butt event; wherein thetransmission further comprises a means for clearing the tooth buttevent, and wherein the means for clearing the tooth butt event comprisesthe controller further comprising a friction brake control circuitstructured to modulate a speed of at least one of the twin countershaftsin response to the tooth butt event.
 11. The transmission of claim 10,wherein the means for clearing the tooth butt event comprises a meansfor controlling a differential speed between shafts operationallycoupled to the gear mesh to a selected differential speed range.
 12. Atransmission, comprising: an input shaft configured to couple to a primemover; twin countershafts having a first plurality of gears mountedthereon; a main shaft having a second plurality of gears mountedthereon; an output shaft selectively providing a torque output to adriveline; a shift actuator structured to selectively couple the inputshaft to the main shaft by rotatably coupling at least one of the firstplurality of gears to the twin countershafts and the second plurality ofgears to the main shaft, wherein the shift actuator is mounted on anexterior wall of a housing, and wherein the twin countershafts and themain shaft are at least partially positioned within the housing; aclutch actuator housing, wherein a clutch actuator is positioned atleast partially within the clutch actuator housing; a controllercomprising a shift characterization circuit structured to determine thata transmission shift operation is experiencing a tooth butt event;wherein the transmission further comprises a means for clearing thetooth butt event and wherein the means for clearing the tooth butt eventcomprises a means for controlling a differential speed between shaftsoperationally coupled to the gear mesh to a selected differential speedrange, wherein the selected differential speed range comprises at leastone speed range value selected from the speed range values consistingof: less than a 200 rpm difference; less than a 100 rpm difference; lessthan a 50 rpm difference; about a 50 rpm difference; between 10 rpm and100 rpm difference; between 10 rpm and 200 rpm difference; and between10 rpm and 50 rpm difference.
 13. A transmission, comprising: an inputshaft configured to couple to a prime mover; twin countershafts having afirst plurality of gears mounted thereon; a main shaft having a secondplurality of gears mounted thereon; an output shaft selectivelyproviding a torque output to a driveline; a shift actuator structured toselectively couple the input shaft to the main shaft by rotatablycoupling at least one of the first plurality of gears to the twincountershafts and the second plurality of gears to the main shaft,wherein the shift actuator is mounted on an exterior wall of a housing,and wherein the twin countershafts and the main shaft are at leastpartially positioned within the housing; a clutch actuator housing,wherein a clutch actuator is positioned at least partially within theclutch actuator housing; a controller comprising a shiftcharacterization circuit structured to determine that a transmissionshift operation is experiencing a tooth butt event; wherein thetransmission further comprises a means for clearing the tooth buttevent, and wherein both of the clutch actuator and the shift actuatorare powered by a common air supply, and wherein the transmission doesnot include any external pneumatic hoses.
 14. A transmission,comprising: an input shaft configured to couple to a prime mover; twincountershafts having a first plurality of gears mounted thereon; a mainshaft having a second plurality of gears mounted thereon; an outputshaft selectively providing a torque output to a driveline; a shiftactuator structured to selectively couple the input shaft to the mainshaft by rotatably coupling at least one of the first plurality of gearsto the twin countershafts and the second plurality of gears to the mainshaft, wherein the shift actuator is mounted on an exterior wall of ahousing, and wherein the twin countershafts and the main shaft are atleast partially positioned within the housing; a clutch actuatorhousing, wherein a clutch actuator is positioned at least partiallywithin the clutch actuator housing; a controller comprising a shiftcharacterization circuit structured to determine that a transmissionshift operation is experiencing a tooth butt event; wherein thetransmission further comprises a means for clearing the tooth buttevent; a planetary gear set comprising a sun gear and a ring gear,wherein the ring gear is coupled to the output shaft, and wherein thesun gear is selectively coupled to the ring gear; a ball bearingoperatively positioned between the sun gear and the ring gear; andwherein each of the twin countershafts comprises helical gearsconfigured to apply thrust loads to the ball bearing.
 15. Atransmission, comprising: an input shaft configured to couple to a primemover; twin countershafts having a first plurality of gears mountedthereon; a main shaft having a second plurality of gears mountedthereon; an output shaft selectively providing a torque output to adriveline; a shift actuator structured to selectively couple the inputshaft to the main shaft by rotatably coupling at least one of the firstplurality of gears to the twin countershafts and the second plurality ofgears to the main shaft, wherein the shift actuator is mounted on anexterior wall of a housing, and wherein the twin countershafts and themain shaft are at least partially positioned within the housing; aclutch actuator housing, wherein a clutch actuator is positioned atleast partially within the clutch actuator housing; a controllercomprising a shift characterization circuit structured to determine thata transmission shift operation is experiencing a tooth butt event;wherein the transmission further comprises a means for clearing thetooth butt event; and wherein the driveline of the transmission does notinclude any tapered bearings, and wherein enclosure bearings of thehousing of the transmission do not take thrust loads of thetransmission.
 16. The transmission of claim 15, further comprising acast aluminum housing.
 17. The transmission of claim 15, wherein thetransmission comprises a 12-speed truck transmission.
 18. Atransmission, comprising: an input shaft configured to couple to a primemover; twin countershafts having a first plurality of gears mountedthereon; a main shaft having a second plurality of gears mountedthereon; an output shaft selectively providing a torque output to adriveline; a shift actuator structured to selectively couple the inputshaft to the main shaft by rotatably coupling at least one of the firstplurality of gears to the twin countershafts and the second plurality ofgears to the main shaft, wherein the shift actuator is mounted on anexterior wall of a housing, and wherein the twin countershafts and themain shaft are at least partially positioned within the housing; aclutch actuator housing, wherein a clutch actuator is positioned atleast partially within the clutch actuator housing; a controllercomprising a shift characterization circuit structured to determine thata transmission shift operation is experiencing a tooth butt event;wherein the transmission further comprises a means for clearing thetooth butt event; and an actuator assembly comprising the clutchactuator housing and an integrated actuator housing, the integratedactuator housing operationally coupled to the shift actuator and theclutch actuator housing, and wherein the actuator assembly is mounted ona vertically upper side of the transmission.
 19. The transmission ofclaim 18, wherein the shift actuator and the clutch actuator are poweredby a common air supply, wherein the shift actuator comprises a pluralityof valve banks, wherein the clutch actuator comprises at least onevalve, and wherein no hoses are present between either the common airsupply and the plurality of valve banks, or the common air supply andthe at least one valve.
 20. The transmission of claim 19, wherein theshift actuator comprises the plurality of valve banks operationallycoupled to a plurality of shift forks, and at least one position sensingdevice structured to determine a rail position of each of the pluralityof shift forks.
 21. The transmission of claim 19, wherein the shiftactuator and the clutch actuator are accessible without decoupling theinput shaft from the prime mover.
 22. The transmission of claim 18,wherein the transmission comprises an 18-speed truck transmission havinga 3×3×2 architecture.
 23. A transmission, comprising: an input shaftconfigured to couple to a prime mover; twin countershafts having a firstplurality of gears mounted thereon; a main shaft having a secondplurality of gears mounted thereon; an output shaft selectivelyproviding a torque output to a driveline; a shift actuator structured toselectively couple the input shaft to the main shaft by rotatablycoupling at least one of the first plurality of gears to the twincountershafts and the second plurality of gears to the main shaft,wherein the shift actuator is mounted on an exterior wall of a housing,and wherein the twin countershafts and the main shaft are at leastpartially positioned within the housing; a clutch actuator housing,wherein a clutch actuator is positioned at least partially within theclutch actuator housing; a controller comprising a shiftcharacterization circuit structured to determine that a transmissionshift operation is experiencing a tooth butt event; wherein thetransmission further comprises a means for clearing the tooth buttevent; and wherein the clutch actuator is pneumatically activated,wherein the clutch actuator has a first extended position and a secondretracted position, and wherein the clutch actuator includes a near zerodead air volume in the second retracted position.
 24. The transmissionof claim 23, wherein the controller further comprises a shift controlcircuit is structured to modulate a first actuating pulse command inresponse to a previously determined gear departure position value,wherein the modulating comprises providing the first actuating pulsecommand as a full open command in response to a position of the shiftactuator being on an engaged side of the gear departure position value,and wherein the modulating further comprises providing the firstactuating pulse command as a pulse-width modulated (PWM) command inresponse to the position of the shift actuator being one of approachingor exceeding the gear departure position value.
 25. The transmission ofclaim 24, wherein the shift control circuit is further structured toprovide a second opposing pulse command in response to a shift actuatorposition indicating an engaging synchronizer is off the block, and tointerrupt at least one of the first actuating pulse command and thesecond opposing pulse command to synchronize pressure decay in a firstclosed volume and a second closed volume, wherein pressure in the firstclosed volume urges the shift actuator into an engaged position andwherein pressure in the second closed volume urges the shift actuatorinto a disengaged position.
 26. A transmission, comprising: an inputshaft configured to couple to a prime mover; twin countershafts having afirst plurality of gears mounted thereon; a main shaft having a secondplurality of gears mounted thereon; an output shaft selectivelyproviding a torque output to a driveline; a shift actuator structured toselectively couple the input shaft to the main shaft by rotatablycoupling at least one of the first plurality of gears to the twincountershafts and the second plurality of gears to the main shaft,wherein the shift actuator is mounted on an exterior wall of a housing,and wherein the twin countershafts and the main shaft are at leastpartially positioned within the housing; a clutch actuator housing,wherein a clutch actuator is positioned at least partially within theclutch actuator housing; a controller comprising a shiftcharacterization circuit structured to determine that a transmissionshift operation is experiencing a tooth butt event; wherein thetransmission further comprises a means for clearing the tooth buttevent; and a solenoid operated actuator; wherein the controller furthercomprises: a solenoid temperature circuit structured to determine anoperating temperature of the solenoid; a solenoid control circuitstructured to operate the solenoid in response to the operatingtemperature of the solenoid, wherein the operating comprises providingan electrical current to the solenoid, such that a target temperature ofthe solenoid is not exceeded.
 27. A transmission, comprising: an inputshaft configured to couple to a prime mover; twin countershafts having afirst plurality of gears mounted thereon; a main shaft having a secondplurality of gears mounted thereon; an output shaft selectivelyproviding a torque output to a driveline; a shift actuator structured toselectively couple the input shaft to the main shaft by rotatablycoupling at least one of the first plurality of gears to the twincountershafts and the second plurality of gears to the main shaft,wherein the shift actuator is mounted on an exterior wall of a housing,and wherein the twin countershafts and the main shaft are at leastpartially positioned within the housing; a clutch actuator housing,wherein a clutch actuator is positioned at least partially within theclutch actuator housing; a controller comprising a shiftcharacterization circuit structured to determine that a transmissionshift operation is experiencing a tooth butt event; wherein thetransmission further comprises a means for clearing the tooth buttevent; and wherein both of the clutch actuator and the shift actuatorare powered by a common air supply; the controller further comprising: aclutch control circuit structured to command a position of the clutchactuator; wherein the clutch control circuit and the shift controlcircuit are further structured to perform at least one coordinationaction selected from the coordination actions consisting of: ensuringthat no two actuating valves are open at the same time; alternatingvalve actuation commands; receiving an air source pressure value from asource pressure sensor of the transmission, and operating valvessimultaneously in response to the air source pressure value beingsufficient; and receiving the air source pressure value from the sourcepressure sensor of the transmission, and compensating commands inresponse to the air source pressure value.